DE2856783A1 - LIFTING DEVICE FOR MOTOR VEHICLES ETC. - Google Patents

Description

DR.-ING. WALTER ABITZ DR. DIETER F. MORF DIPL.-PHYS. M. GRITSCHNEDER

Patent attorneys

Munich.

December 29, 1978

Postal address / Postal Addresä PO Box 8601O9, 8OOO Munich 8Θ

Flenzenauerstraße 28

Telephone 9S 32 22

Telegrams: Chemindus Munich

Telex: CO) 523993

JOHA 4C

ROLF GUSTAF JOHANSSON

Jacob.Dubbes Vag 13, S-13011 Saltsjo-Duvnas,

Shredding

Lifting device for motor vehicles and the like.

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The invention relates to the lifting of objects, for example motor vehicles. Is according to the invention a standing one. Mast section is provided in which are fixed: a lifting motor, a lifting arm, the inner end of which is slidably mounted along the mast section, from which the arm extends freely outwards, and a lifting fork that connects to the free end of the lifting arm is articulated so that the object to be lifted is held by the lifting arm and the lifting fork can be.

A lifting device of this type is known from Swedish patent specification 72 13 247-5, which in comparison to other known lifting devices with two or four standing masts the main advantages are a safe way of working, Has simplicity in construction etc. Compared to a lifting device, which is generally based on the principle a forklift is constructed, this known device works advantageously as follows: _ the lifting arm and their lifting fork move a certain distance upwards along the standing mast in a horizontal and parallel position to each other, the continuous upward movement along the standing mast by stops is changed, which cause the pivoting of the lifting fork at its linkage on the lifting arm. When the lifting arm and the lifting fork are V-shaped to each other, with the vehicle floor assembly or the wheels on these lifting elements rest, the lower part of the vehicle becomes easily accessible. When using the known device mentioned, the pivoting movement between the lifting arm and the lifting fork result in the vehicle being inclined towards the mast section, which is undesirable for certain purposes.

JOHA 4C Λ

The invention is based on this disadvantage avoid and develop a lifting device for lifting a vehicle, for example a motor vehicle, in which the lifting arms first form the V-shape without tilting the vehicle, and second, the lifting arms can be raised vertically along the standing mast section to the desired working height. The inventive Lifting device is designed so that there is a risk that the vehicle accidentally falls or from a raised Position drops, is switched off. For this purpose there are a number of locking devices according to the invention provided both hydraulic and mechanical type, which operate independently of each other can.

The following is a preferred embodiment of the invention described in more detail in connection with the accompanying drawings, namely show:

1 shows a side view of a lifting device according to the invention, in which the lifting arms are in the lowest position;

FIG. 2 is a view similar to FIG. 1 with the lifting arms in the raised position; FIG.

3 is a sectional view of the lower part of the mast with the ends of the lifting arm and the lifting fork in FIG the lowest position;

FIG. 4 is a sectional view similar to FIG. 3, but showing the lifting arm and the lifting fork after completion their pivoting movement shows and

Pig. 5 is a sectional view similar to FIGS. 3 and 4, showing the lifting fork and the lifting arm in a partially

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se shows raised position.

The lifting device according to the invention has a vertical mast section 1, a lifting arm. 2, which differs from the front part of the mast 1 extends outwards and its inner ends for sliding up and down movement are mounted on the mast, and a lifting fork 3, which is articulated to the outer ends of the lifting arm 2 is. The mast 1 is preferably made of two U-iron or double T-beams la, which are vertical and each other are arranged opposite and parallel to each other, the upper and rear parts of the same are rigidly connected to one another in the transverse direction and the lower parts thereof are arranged on a floor plate Ib are. At the lower part of the mast section la a wedge-shaped part Ic is shown, the tracks for rollers has, as well as a power source, which is described in more detail below. A guide beam (not shown) for the inner ends of the lifting arm 2 can be arranged in a parallel position to the two mast sections la and with the upper end of the mast section and connected to the base plate Ib. This leadership carrier serves as a transition the downward forces on the mast sections and to protect the between the mast sections Lifting motor.

At the lower part of the mast, a number of mounting brackets Id are shown in which the hollow sections le, If zur Forming a fixed base part can be used to support the standing mast 1. If desired, you can the lower sections Ie and If with suitable retractable Wheels (not shown) are equipped to make the whole lifting device easier to store.

The lifting arm 2 preferably consists of two parallel ones

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Side beams 2a, which-together by cross pieces are connected to form a rigid assembly. The inner part of at least one carrier 2a (preferably of the two beams) is provided with a lever 2b which extends upwards at an obtuse angle. The inner ends of the beams are hinged at 7 to a hoist motor 15 as below is described in more detail.

A freely rotatable roller 4 is mounted on the upper free end of each lever 2b. The role of the roller 4 is longitudinal a guide rail 9-10 to roll in the stand 1 when the lifting arm 2 is raised or lowered by the lifting motor 15 will. Each guide rail has a lower part 10 which consists of a welded plate which is arranged in each extended lower part of the upright support la and extends to the inner surface of the front flanged part 9 of the standing beam la extends to which it is attached and along which it extends in extends longitudinally upwards.

The angle between the support 2a and the lever 2b and the angle between the upper and lower parts of the The guide rail is adjusted so that when the lifting arm 2 is in its lowest position, the roller 4 is in contact with the lower part 10 of the. Guide rail is located. The lifting arm 2 is in this position parallel to and adjacent to the ground. When the pivot point of the attachment on the lifting arm 2 is raised, moves the roller 4 moves up along the inclined part 10 of the guide rail, moving forward towards the front Flange 9 moves, with the result that lever 2b and carrier 2a are pivoted about point 7. If the Roll 4 the intersection between the inclined rail

_ 4 _
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part 10 and the vertical straight part 9 reached, the carrier 2a (Fig. 4) maintains a fixed inclined position at. During the continuous upward movement of the hinge point 7, the roller 4 moves along the vertical part 9 of the guide rail and the lifting arm 2 is raised and remains in its inclined position. When the pivot point 7 is then lowered, the lifting arm performs the same movements in reverse.

The lifting fork 3, which is connected to the free end of the lifting * arms 2 is articulated, consists of two parallel beams 3a, which are preferably connected to one another at their inner end by a plate 3c. The articulation 3b extends perpendicular to the lever arm 2 and through the middle of the fork-like arms 3a. At the inner end of the lifting arm 3, a freely rotatable roller 5 is provided. The rollers 5 are arranged so that they are with a rail come into contact, which is preferably the outer surface the flanges 9 of the upper mast section la is. When the inner end of the lifting arm 2 is raised, as before described, and when the lifting arm is angled down at the same time, the joint 3b moves between the Lifting arm 2 and the lifting fork 3 upwards and to the standing mast section. This has the consequence that the carrier 3a of the Lifting fork 3 is pivoted upwards around the shafts of the rollers 5, so that these act as a fixed pivot point for the lifting fork 3 works. When the lifting arm 2 reaches its inclined end position, as described above and vertically upwards begins to wander, maintaining his inclined position, the hinge axis 3a follows in the same direction, taking the lifting fork 3 with it and the rollers 5 rolling upwards in contact with the guide rails 8.

It should be mentioned that the inclination of the lifting arm 2 and the lifting fork 3 can be changed in that the

909828/0832

Length and / or the angle of the aforementioned elements can be changed. From the foregoing it can be deduced that the lifting sequence brought about by the lifting motor 15 is such that, firstly the lifting arm 2 and the lifting fork 3 are moved to form a V-shape with each other and the lifting object lift something off the ground. The lifting arm and lifting fork are then raised vertically to a desired height and the V-shape is maintained without tilting the raised object. The latter rests on a support 6a, which is articulated on the inside of the lifting arm 2, and on a support 6b that is pivotable and is slidably arranged on the outside of the lifting fork 3. The pivot pins for these supports are parallel to the joint axis 3b. The distance between the supports is maintained by a spacer 6c. The supports 6a and 6b can be of a conventional type and can be constructed to fit a motor vehicle carry it on its frame, or built so that it carries it with its wheels. Since these supports are not according to the invention Step, they are not described in detail below.

The lifting motor is a linear motor and is vertically in the middle between the mast supports la of the standing mast section 1 arranged. A hydraulic motor with a piston and a cylinder is preferably used, but it can also be used a rack and pinion drive motor or a worm drive motor can be provided. As shown in the drawings, acts The lifting motor 15 is a hydraulic motor with a cylinder 16 in which a primary piston arrangement 17 is movable which consists of a piston and a piston rod through which a cylindrical bore is provided is. A second piston and piston rod assembly 18

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is slidable in the longitudinal direction in the cylindrical bore of the first piston assembly 17. Two radially protruding Shoulder joints 19 on the cylinder 16 serve as bearings for the upper part of the two tie rods 20, whose lower ends are articulated to the articulation 7 of the inner end of the lifting arm 2. This arrangement makes it possible to lower the hinge axis 7 onto the base plate Ib of the standing mast section on which the lifting arm 2 is in its lowest position, i.e. in a horizontal position.

In a similar way, there are two diametrically opposite one another on the outer side part of the piston assembly 17 of the cylinder radially extending lugs 21 are provided. At the point that is closest to the standing mast section is the arm 3a of the lifting fork 3 is equipped with an extension element 22 which is the axis for the rollers 5 of the Bypasses the lifting fork and forms a fork which encloses the lifting motor 15.

The extension element 22 is provided with a groove 23 which is arranged in the upper part of the extension element 22 and the lugs 21 of the first primary piston assembly 17 receives.

The secondary extensible piston assembly 18 is connected within the primary piston assembly 17 and rests with its piston end on the base plate 1b of the standing mast section 1. The effective cross section the secondary piston assembly 18 has a smaller area than the corresponding area of the primary Piston assembly 17.

When a pressure medium through a hydraulic pump (not shown) or by other means through the tubular piston rod

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of the secondary piston assembly is fed to the upper closed part of the cylinder 16 when the whole Lifting device is in its lowest position shown in Figure 3, i.e. when the primary and secondary Piston assembly are fully inserted into one another and into the cylinder 16, the pressure medium causes a thrust effect on the inner surface of the pistons. Since the cross section of the primary piston arrangement 17 has a larger surface area than that of the secondary piston assembly 18, movement first occurs between the cylinder 16 and the piston assembly 17 as a result of the relative distribution of the piston cross-sections, as explained, instead. The secondary piston assembly 18 maintains its position in the primary piston assembly. The primary movement has the consequence that the Cylinder 16 is raised, with it over the shoulder joints 19, the tie rods 20 and the joint axis 7 the inner The end of the lifting arm 2 takes with it. When the rollers move along the guide rail 10, the lifting arm is thereby pivoted into an outwardly and downwardly inclined position. At the same time, the primary piston assembly 17, which remains stationary, has the consequence that the inner end of the Arms 3a of the lifting fork on the lower part of the standing mast section remains, since the noses21 are in contact with the Extension 22 of the lifting fork are located. In this way, the arms 3a are pivoted upwards, with the rollers 5 serve as bearings and joints.

When the cylinder 16 reaches the end of its certain stroke length in the primary piston unit 17, the reach Rolls 4 of the lifting arm 2, the vertical straight part 9 of the guide rail 9 - IO and the lifting arm 2 and the lifting fork 3 remain in a fixed inclined position. The pressure medium then pushes the secondary piston assembly 18 out of the primary piston arrangement 17, whereby the primary piston arrangement 1.7 and the cylinder 16 remain unchanged

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are raised with respect to each other, with the lifting arm 2 and the lifting fork 3, also unchanged in relation to one another, to take with oneself.

The ratio between the areas of the piston assemblies 17, 18 on which the pressure medium acts, represents a hydraulic safety function, so that the movements described above inevitably proceed in the sequence described above, i.e. the lifting arm and the lifting fork first form the desired one V-shape and then move vertically in this V-shape. When lowering, of course, the aforementioned movements take place in reverse order.

The lifting device according to the invention also has a hydraulic safety device. As described above, is the cylinder of the lifting motor 15 with a pressure medium from a pump via the secondary tubular Piston assembly 18 fed, with the result that the lifting arm 2 and the lifting fork 3 si "*! From their lowest Move position up. The lowering process is brought about that the pressure medium from the cylinder 16 is released through a central bore 24 in the secondary piston assembly 18 and through that bore 24 a relief valve 25 is provided, which is designed so that the volume of the released in this way Pressure medium is constant regardless of the pressure in the cylinder 16. The formation of such a relaxation or Release valve 24, which regulates the oil flow, is the Known to those skilled in the art and is therefore not described in more detail here. When the supply of pressure medium from the pump to the cylinder 16 turned off and a mechanical safety device, which is described in more detail below, ineffective by hand is done, the lifting arm 2, the lifting fork 3 and the load carried move downwards under their own weight,

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whereby the pressure medium is displaced to the outside through the bore 24 and the valve 25. Because the current is controlled constantly and independently of the pressure in the cylinder 16, the lowering speed is constant regardless of a large or small load or when there is no load on the lifting fork and on the lifting arm is located. The valve 25 is designed in a conventional manner so that it stops any oil flow, if there is a break in the cylinder or in the pump lines or if the operation of the pump is disturbed, whereby the lowering is automatically brought to a standstill. The lifting device according to the invention has a Number of mechanical safety devices designed to operate in all conditions works in the intended way. These mechanical safety devices are different from those previously described Hydraulically operating safety devices completely independently, so that a large number of safety functions are performed by the device according to the invention will.

On the lower part of the standing mast section 1 there are lugs 26 which extend from the front part of each support element 1 a of the standing mast section extend outwards and at the inner ends of the arm 3 a of the lifting fork 3 when the latter is in the lowest position. The noses 26 prevent mechanically, that the inner ends of the arms 3a move upwards when the lifting movement is initiated so that the lifting fork 3 is pivoted up to its outer and upper inclined position under all conditions. If the Lifting fork 3 has reached this position, the inner ends of the arms 3a of the mast section 1 have one Amount moved outwards, so that they are from the lugs 26

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are released and therefore the lifting fork and the lifting arm can be raised vertically, as already described.

A locking rail 27 is connected to the extension element 22 the lifting fork 3 is articulated and extends between the levers 2b of the lifting arm 2 and the lifting motor 15. At its upper end, the locking rail 27 is provided with a stop surface 28 and the lever 2b of the Lifting arms 2 are provided with a similar stop surface 29, preferably in the form of a cross piece between the free ends of the levers 2b and behind the levers and rollers 4. When the lifting arms and the Lift fork are in their lowest position, the locking bar 27 extends with an inclined position of the extension elements 22 between the lifting motor and the stop surface 29 upwards and v / ird in this Position by an elastic retractable force, preferably by a solid rubber cushion, between the locking bar 27 and the lifting motor 15 held. During the primary lifting operation, levers 2b become the lifting fork pivoted to the front part of the standing wall section 1 and to the lifting motor 15, the stop surface 29 on the back of the locking rail 27 comes to rest and the locking rail 27 gradually in a substantially vertical position slides. When the lifting process has reached the point at which the lifting arm has the desired incline Has taken position, the stop surface 28 of the locking rail 27 moves below the stop surface 29 of the lever 2b and in contact with this, in which locking position it is held under elastic force. The locking bar secures and blocks a distance between the inner ends of the lifting arm 2 and the lifting fork 3 equal to the length the locking bar 27 is and with respect to the desired

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Inclination of the lifting arm 2 to the lifting fork 3 is set.

The lower part of the locking rail 22 is with a itself to the rearwardly extending lever 30 rigidly connected. During the lowering process, the lever 30 comes into contact with the base plate Ib of the standing mast section 1 via a compression spring arranged on the lever 30. The contact with the base plate is provided so that it is a brief moment before the relative pivoting movement between the Lifting arm 2 and the lifting fork 3 begins to take place, so that the locking bar 27 is pivoted to the lifting motor 15, with the result that the locking surface 28 is released from the locking surface 29, whereby a further movement between the lifting arm 2 with respect to the lifting fork 3 allows will.

The levers 2b of the lifting arm 2 are each provided with pivotally attached ratchet wheels 31, which with each other through a cross piece connected and against the rear vertical flanges 32 of the respective standing mast section la are spring-loaded in such a way that they connect with - '· ■ a number of locking lugs 33, which in certain Heights from the base and are fixedly attached to the rear vertical flanges 32 of the mast section. By the use of these locking wheels 31, the lifting arm 2 and the lifting fork 3 can be at any desired lifting height be blocked. At the same time, the locking bar mechanically prevents any pivoting movement between the lifting arm 2 and the lifting fork 3 to maintain the desired V-shape between the parts. When lowering, the ratchet wheels 31 prevented from engaging the locking lugs 33 by a hand-operated handle 34. Of the Handle 34 is preferably connected to a vertical rod extending from the enlarged wedge-shaped part Ic

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of the standing mast section 1 to the upper part of the mast section between the locking lugs and the locking wheels 31 connecting crosspiece extends. The vertical rod 35 is eccentrically supported in bearings at both ends. By pivoting the handle 34, the rod 35 is rotated and due to its eccentric Storage, the locking wheels 31 pushed outward regardless of the respective lifting height.

The lifting device described above was only used in connection with a particular embodiment of the Invention described, but can be improved in various ways within the scope of the invention. For example, the standing mast section 1 can be fixedly attached to a wall instead of on a foundation to rest. The standing mast section can be built in this way v / ground that it receives two lifting arms 2 with accompanying lifting forks 3, which are opposite each other to the outside extend and are provided with their respective actuators.

End of description.

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Claims (1)

Claims; 1. Device for lifting an object, marked by a standing vertical mast section (1), a substantially linear lifting motor (15), which in the mast section is incorporated, a lifting arm (2), the inner end of which is slidably disposed on the mast section and extends freely outward therefrom, which inner end is articulated with the motor (15) is connected, and a lifting fork (3) which is articulated to a free end of the lifting arm (2) is which lifting arm and the lifting fork in their lowest position extend horizontally outwards from the mast section extend with the inner ends of the arm and the fork articulated and vertically movable on the mast section are guided in such a way that when the mentioned inner end of the lifting arm is first out vertically the mentioned lowest position by the lifting motor (15) a given upward distance along the mast section is shifted, the lifting arm is pivoted about its inner end to an outwardly and downwardly inclined position and the lifting fork around its inner end to an outward and upward inclined position, whereupon the lift motor causes the inner end of the lift arm to move a further distance along said mast section moved upwards and causes the inner end of the lifting fork to shift, but the relatively small 09828/0832 ^ 856783 JOHA 4C inclined position of the lifting arm and lifting fork is maintained. 2. Device according to claim 1, characterized in that that the lifting arm (2) has at least two rigidly connected supports (2a) which are parallel to one another extend, and the lifting fork (3) has at least two supports (3a) which extend parallel to each other and the central portion of which is articulated to the free end (3b) of the lifting arm. 3. Apparatus according to claim 1, characterized by a support (6a) for the mentioned object, which is adjacent the inner end of the lifting arm (2) is articulated, and a support (6b) at the outer end the lifting fork is articulated and slidable in the longitudinal direction, with a spacer (6c) between the supports (6a, 6b) is provided. Apparatus according to claim 2, characterized in that the lifting arm (2) further extends upwards Has lever (2b) which form an obtuse angle with the aforementioned supports (2a) of the lifting arm and are provided at their free ends with rollers (4) which have a rolling surface in the standing mast section (1) contact which rolling surface by an upper straight part (9) and a lower inclined part (10) is formed, which the latter forms an obtuse angle with the straight upper section and follows 909828/0832 ^ 856783 JOHA 4C -J- extends down and away from the lift arm. 5. Apparatus according to claim 4, characterized in that the carrier elements (3a) of the lifting fork (3) at their inner ends are provided with rollers which contact a second straight vertical surface on the mast section, during the initial movement of the lifting fork, these rollers first act as a fixed bearing for the Lifting fork act and then act as a roller bearing on the mentioned second surface during the vertical lifting of the lifting arm together with the lifting fork. 6. Apparatus according to claim 5, characterized in that the mast section has two vertical parallel double T-rails (la) with flanged parts (9-10) which are in alignment with each other and each other directly are arranged opposite one another, with the upper part of the rolling surface for the rollers of the lifting arm through the inner surface of at least one of the flanged parts is formed, while the lower part of the rolling surface consists of an inclined plate which extends to the aforementioned inner surface, while the outer surface of the flanged parts forms a guide rail for the rollers of the lifting fork. 7. Apparatus according to claim 5, characterized in that the lifting motor (15) consists of a hydraulic jack with a cylinder (16) and a primary piston unit (17) which is movable in this cylinder, and from a secondary piston unit (18), which is in the 909828/0832 JOHA 4C -t- primary piston unit (17) is movable, wherein the one part of the secondary piston unit rests on a support which is attached to the mast section is which primary piston unit and cylinder are hinged to the inner end of the lifting arm, part of the primary piston unit that consists of the. Cylinder protrudes, is provided with a stop, at which an extension element (22) can come to rest on the lifting fork, which extension element surrounds the rollers (5) and the support elements of the lifting fork. 8. Apparatus according to claim 7, characterized in that that the primary piston unit (17) has a larger effective surface area than the secondary piston unit (18), so that when a pressure medium is supplied, the primary piston unit first comes out of the cylinder its full stroke length and, secondly, the secondary piston unit telescopes out of the primary piston unit is moved out until a desired lifting height is reached. 9. Apparatus according to claim 8, characterized in that the stroke length of the primary piston unit (17) is the same is the vertical distance between the inner ends of the lifting arm (2) and the lifting fork (3) when the mentioned carrier elements are in said inclined position. 10. Apparatus according to claim 9, characterized in that the lifting motor (15) with a pump for the supply - 4 909828/0832 JOHA 4C the pressure medium is connected to lift the lifting fork (3) and the lifting arm (2) together with the object, and a valve (25) at the free end of the secondary piston unit (18) for releasing the pressure medium is provided when the lifting arm (2) and the lifting fork (3) are lowered together with the object will. 11. The device according to claim 10, characterized in that the valve (25) is designed so that the for Pump returning pressure medium flow remains constant regardless of the pressure generated by the lift motor (15) is exercised in order to keep the lowering speed constant. 12. The device according to claim 11, characterized in that the valve (25) is designed so that it is the Pressure medium flow from the lifting motor (15) blocked in the event of an unforeseen break. 13. Apparatus according to claim 12, characterized by a console (Id) on the lower part of the mast section, which at least one edge of the support elements of the Lifting fork can reach over, v / hen the lifting fork is in a horizontal position to a to prevent vertical movement of this edge and to allow free upward movement of the mentioned edge, when the lifting fork has reached its outward and upward inclined position. 909828/0832 JOHA AC 14. Device according to claim 13, characterized in that that at the end of the extension element (22) of the lifting fork (3) a locking rail (27) is pivotably mounted so that it is connected to a stop surface (29) on the levers (2b) of the lifting arm (2) comes to rest when the lifting arm and the lifting fork reach their inclined position have which locking bar secure the arm and fork 'in the mentioned inclined position. 15. The device according to claim 14, characterized in that the Spsrrschiene (27) is elastically loaded and pressed to the stop surface (29) and also carries a rigidly connected, rearwardly extending lever (30) at its lower part, which with a Federab- ¹ support surface (Ib) of the mast section can come into contact in order to pivot the locking rail away from the stop surface. .16. Device according to Claim 15, characterized by Locking wheels (31) on the lifting arm (2) which are spring-loaded for engagement with locking lugs (33) which are on the mast section are attached at different heights and the lifting arm (2) and the fork (3) in the desired Lock lift heights, which ratchet wheels are out of engagement with the locking lugs by a manually operated Handle (34) can be brought. 909828/0832