A pattern-forming method includes providing a resist film on a substrate using a radiation-sensitive composition. The resist film is exposed. The exposed resist film is developed using a developer solution. The developer solution includes no less than 80% by mass of an organic solvent. The radiation-sensitive composition includes at least two components including a first polymer and a radiation-sensitive acid generator. The first polymer includes a structural unit having an acid-labile group. One or more components of the radiation-sensitive composition have a group represented by a formula (1). A− represents —N−—SO2—RD, —COO−, —O− or —SO3−. —SO3− does not directly bond to a carbon atom having a fluorine atom. RD represents a linear or branched monovalent hydrocarbon group, or the like. X+ represents an onium cation. —A−X+ (1)

Provided are a solid catalyst for propylene polymerization and a method for preparing the same, specifically a solid catalyst for propylene polymerization which does not contain any environmentally harmful material and can produce a polypropylene having excellent stereoregularity with a high production yield, and a method for preparing the catalyst.

Catalyst component for the polymerization of olefins comprising Mg, Ti and an electron donor compound of the following formula (I) In which R1 to R4 groups, equal to or different from each other, are hydrogen, C1-C15 hydrocarbon groups, optionally containing an heteroatom selected from halogen, P, S, N and Si, R6 group is selected from C1-C15 hydrocarbon groups optionally containing an heteroatom selected from halogen, P, S, N and Si, and R5 is selected from phenyl groups mono or poly substituted with halogens, said groups R1-R4 being also optionally linked to form a saturated or unsaturated mono or poly cycle.

The present invention relates to a process for the production of propylene polymers in the presence of a Ziegler-Natta catalyst comprising a titanium compound having at least one titanium-halogen bond, and a blend of a diether compound and a succinate compound as internal electron donor, all supported on a magnesium halide in active form, an organoaluminium compound and an optional external donor.

After a cyclopentadiene compound and a vinyl aromatic compound are thermally polymerized, the obtained copolymer is subjected to a hydrogenation reaction to form a hydrogenated product. After most of the hydrogenation solvent is separated by a solvent evaporation tank from the hydrogenated product, an additive separately prepared by dissolving an antioxidant is added to the hydrogenated product to form a mixture. While the hydrogenation solvent is a naphthenic solvent, the additive is prepared by dissolving the antioxidant in an aromatic additive solvent having the same carbon atoms as those of the hydrogenation solvent. Then, the low-molecular-weight component as well as the remaining hydrogenation solution and the additive solvent are separated by a thin-film evaporator from the mixture. The obtained molten resin is pelletized to produce hydrogenated petroleum resin pellets. The time for uniformly blending the antioxidant can be shortened.

A polymer reactor-blend comprising at least a first component having a polydispersity index of greater than about 20 and is present in an amount of from about 1 wt. % to about 99 wt. % based on the total weight of the polymer and a second component having a polydispersity index of less than about 20 and is present in an amount of from about 1 wt. % to about 99 wt. % based on the total weight of the polymer wherein a molecular weight distribution of the second component lies within a molecular weight distribution of the first component.

The present disclosure provides a system for recovering emissions generated from an olefin polymerization process, comprising: a devolatilizer for receiving a fresh sweep gas and emissions generated from the olefin polymerization process and outputting a first fluid and a polyolefin resin; a compression refrigeration unit including a compression device and a first heat exchange device, for receiving said first fluid and outputting a first gas-liquid mixture; a first gas-liquid separation device for separating the first gas-liquid mixture and outputting a first recovery product and a first gas phase composition; a first gas separation device for receiving the first gas phase composition, removing small molecular substances therefrom, and outputting a composition rich in small molecular gases and a second gas phase composition rich in hydrocarbons; and a second gas separation device having a second heat exchange device, a second gas-liquid separation device, and a first gas expansion device.

The present invention relates to a production method for efficiently obtaining an acrylic acid-based polymer having a narrow molecular mass distribution and a low molecular mass, without using a large amount of chain transfer agent. A method for continuously producing an acrylic acid-based polymer obtained by continuously polymerizing a monomer having acrylic acid as an essential component, characterized in that a liquid feed pump applies a mechanical load of 0.5 to 2.5 kJ/L to the liquid discharged from the outlet of a reactor. An acrylic acid-based polymer having fewer high-molecular-mass components, excellent dispersion and other properties, and a low molecular mass is thereby obtained.

Provided is a fluorine- and epoxy group-containing copolymer with excellent workability at room temperature, high water-repellency, and excellent characteristics as a water vapor barrier. Also provided is an efficient method for producing said copolymer. The fluorine and epoxy group-containing copolymer is characterized by containing at least a monomer unit represented by general formula (1): {Therein, R1-R10 each independently represent an alkyl group having 1-3 carbon atoms or a hydrogen atom, R11 is a hydrogen atom, methyl group, or phenyl group, and R5 or R6 can be linked with R7 or R8 to form a ring.} and a monomer unit represented by general formula (2): {Therein, R12 and R13 each independently represent a hydrogen atom or a fluorine atom; R14 represents a hydrogen atom, fluorine atom, methyl group or trifluoromethyl group, and R15 represents a flourine atom or perfluoro group having at most 12 carbon atoms}.

A method for producing highly reactive olefin polymers wherein at least 50 mol. % of the polymer chains have terminal double bonds, and a novel polymerization initiating system for accomplishing same.

In a process for producing polyethylene having a molecular weight of at least 3×105 g/mol as determined by ASTM 4020, ethylene is contacted under polymerization conditions with a slurry of a catalyst composition in at least one hydrocarbon. The catalyst composition comprises a Group 4 metal complex of a phenolate ether ligand and the slurry includes from about 5 to less than 40 ppm per liter of a compound effective to increase the conductivity of said at least one hydrocarbon.

Polyolefin production using an improved catalyst system and, in particular, a method for production of a polyolefin is disclosed. One or more monomers are contacted with a catalyst system. The catalyst system includes titanium tetrachloride as a catalyst precursor and magnesium ethylate as a support for the catalyst precursor. The catalyst system also includes a hydrocarbyl aluminum cocatalyst represented by the formula R3Al, where R is an alkyl radical having 1 to 14 carbon atoms, and where the molar ratio of the hydrocarbyl aluminum cocatalyst to the titanium tetrachloride catalyst precursor ranges from 50:1 to 400:1. The catalyst system also includes a halogenated hydrocarbon as a promoter, where the molar ratio of the halogenated hydrocarbon promoter to the titanium tetrachloride catalyst precursor ranges from 0.001:1 to 300:1.

The present invention provides a diene polymer in which a polar functional group is introduced into an end by radical polymerization, and its production method; a polymer emulsion and a rubber composition each containing the diene polymer; and a pneumatic tire containing the rubber composition. The present invention relates to a diene polymer, which is obtained by radical polymerization of at least one radical polymerizable monomer in the presence of at least one polar functional group-containing thiol compound, and has a polar functional group at at least one end: The polar functional group-containing thiol compound is preferably represented by formula (1): X—R1—SH (1) wherein X represents an ester group, a hydroxyl group, a carboxyl group, an amino group, or an alkoxysilyl group, and R1 represents an alkylene or arylene group which may have a substituent.

The invention relates to free-radical polymerization and free-radical cross-linking and more particularly provides a process of free-radical polymerization or cross-linking wherein at least one polymerizable monomer or at least one compound to be cross-linked is contacted in the presence of at least one selected organic peroxides, characterized in that the organic peroxide is prepared continuously by an ex situ process with the aid of a closed plate exchanger. In the process according to the invention, it's possible to introduce the above selected organic peroxide continuously during the polymerization or cross-linking reaction.

A magnetic particle-polymer hybrid material can include: a substance having a structure of Formula 1 or derivative or salt thereof:Z(Y-Triazole-CH2—X—CH2—(FP)n)m (Formula 1), wherein Z is a magnetic particle smaller than 1 mm; n and m are independently integers; Y includes a first linker having an alkyl and/or aryl linked to the magnetic particle; X is CH2 or a heteroatom; FP is a functionalized polymer having: a first structure derived from a first norbornene compound linked to the magnetic particle through the Y-Triazole-CH2—X—CH2 linker; and one or more monomeric units each including a second structure derived from a second norbornene compound, where one of the monomeric units is linked to the first structure through a saturated or unsaturated alkyl, each monomeric unit includes a functional group capable of binding with another substance.

The present invention is directed to a copolymer comprising: a polymeric backbone chain derived from a monomer comprising at least one conjugated diolefin monomer and optionally at least one vinyl aromatic monomer; and a polymeric side-chain bonded exclusively to a terminal end of the backbone chain, the side-chain comprising a polymer derived from a monomer having a hydrogen bond donor moiety and a hydrogen bond acceptor moiety.

The present description relates to an olefin block copolymer preferably useful to form nonslip pads due to excellences in elasticity and heat resistance, and a sheet-shaped molded body comprising the olefin block copolymer The olefin block copolymer includes a plurality of blocks or segments, each of which includes an ethylene or propylene repeating unit and an α-olefin repeating unit at different weight fractions. The olefin block copolymer satisfies a defined relationship when a load of 5 to 10 kg is applied to a sheet-shaped molded body of the block copolymer for 12 hours or longer at a temperature of 60° C. or higher, and then removed.

A strap comprising a propylene and 1-hexene copolymer containing from 0.3 wt % to less than 5 wt % of 1-hexene derived units said copolymer having a melt flow rate (MFR) determined according to ISO method 1133 (230° C., 2.16 kg ranging from 0.3 to less than 11 g/10 min.

The present application relates to novel monomers comprising polycarbosiloxane monomers useful in certain specific embodiments in the manufacture of devices. More particularly, the present application relates to certain ethylenically unsaturated free radical polymerizable monomers comprising polycarbosiloxane monomers. Even more particularly, the present application pertains to monomers comprising polycarbosiloxane monomers which further comprise at least two ethylenically unsaturated free radical polymerizable groups.

Process for the preparation of etherified melamine/formaldehyde condensates, in which first a methylolation of melamine with a formaldehyde component in the molar ratio of from 1:6 to 1:15, preferably at a pH of >7, is carried out. This is followed by an etherification of the resulting hydroxymethylation intermediate in the presence of a C1-C20-alkyl, preferably of a C1-C6-alcohol, particularly preferably of a C1-C4-alcohol, at a pH of 9.5 being established before, during and/or after the distillation. According to the invention, a plurality of hydroxymethylation, etherification and distillation steps follow in order to achieve an etherified melamine/formaldehyde condensate which is distinguished by a high degree of hydroxymethylation, a high solids content and a low viscosity.

The present invention relates to a polymer composition comprising polylactide and, based on the weight of this polymer, from 17 to 25 wt % of a chain modifier, from 30 to 55 wt % of an elastomeric polymer and from 20 to 45 wt % of a plasticizer. The invention also relates to the method of preparing said composition as well as to the method of manufacturing an article starting from said composition and the article per se.

To provide a water/oil repellent composition which can impart sufficient post-air-drying water/oil repellency to the surface of an article, and which presents a low environmental impact, and an article having its surface treated with the water/oil repellent composition. A water/oil repellent composition comprising a copolymer (A) having structural units based on a monomer (a), structural units based on a monomer (b), structural units based on a monomer (c) and/or structural units based on a monomer (d); and an aqueous medium (B) containing water, and a film-forming assistant (x) and/or a film-forming assistant (y). Monomer (a): a monomer having a C1-6 polyfluoroalkyl group, monomer (b): vinylidene chloride, monomer (c): a monomer, the homopolymer of which has a glass transition temperature of at least 20° C., monomer (d): a monomer having a crosslinkable functional group, film-forming assistant (x): a specific amide solvent, and film-forming assistant (y): a specific glycol solvent.

The present invention provides polymerization processes utilizing a catalyst system containing an ansa-metallocene and a second metallocene compound for the production of olefin polymers.

The present invention provides polymerization processes utilizing an ansa-metallocene catalyst system for the production of olefin polymers. Polymers produced from the polymerization processes have properties that vary based upon the presence or the absence of hydrogen and/or comonomer in the polymerization process.

The present invention relates to a process for preparing a diene elastomer. The invention especially applies to the production of a polybutadiene with a high level of cis-1,4 linkages that has at the same time a Mooney viscosity ML (1+4) greater than or equal to 40, a polydispersity index less than 2.1 and a reduced cold flow and of a polyisoprene. The process according to the invention comprises a reaction of a catalyst system with at least one conjugated diene monomer, this catalyst system being based on at least: one conjugated diene;one organic phosphoric acid salt of one or more rare-earth metals, said salt being in suspension and in at least one saturated and aliphatic or alicyclic, and inert hydrocarbon-based solvent;one alkylating agent composed of an alkyl aluminum for formula AlR3 or HAlR2 anda halogen donor belonging to the family of alkylaluminium halides, with the exclusion of alkylaluminium sesquihalides. This process comprises a separate bringing together of the monomer(s) to be polymerized with at least one alkylaluminium compound of formula AlR3 or HAlR2 which is identical or not to the alkylating agent of said catalyst system, said amount being chosen as a function of the characteristics of the polymerization medium and/or the polymerization conditions and/or said elastomer to be obtained.

A method for preparing a catalyst system for heterogenous catalysis of an isobutylene polymerization reaction includes the steps of forming an alumina support in which the alumina support has pores formed therein, and reacting BF3/methanol catalyst complex with the alumina support. The ratio of methanol to BF3 in the catalyst complex ranges from 0.5 moles to 2 moles of methanol per mole of BF3. The alumina support is formed so as to have pores each having a diameter of greater than twenty nanometers. The alumina support can be in the form of beads or extrudates having a length significantly greater than a diameter. The extrudate can also have a tri-lobe configuration.

A true tetrafluoroethylene (TFE) copolymer of the fine powder type is provided, wherein the copolymer contains polymerized comonomer units of at least one comonomer other than TFE in concentrations of at least or exceeding 1.0 weight percent, and which can exceed 5.0 weight percent, wherein the copolymer is expandable, that is, the copolymer may be expanded to produce strong, useful, expanded TFE copolymeric articles having a microstructure of nodes interconnected by fibrils. Articles made from the expandable copolymer may include tapes, membranes, films, fibers, and are suitable in a variety of end applications, including medical devices.

Provided are: a method for controlling the decoloration reaction rate and color density of a fast light-modulating material to levels suitable for practical use; and a fast light-modulating material having a decoloration reaction rate and a color density which are suitable for practical use. A polymer obtained by polymerizing a paracyclophane-bridged hexaarylbisimidazole compound having a radical-polymerizable group, and a copolymer obtained by copolymerizing the compound with a (meth)acrylic acid compound or a sensitizer having a radical-polymerizable group can achieve controlled decoloration reaction rates, photosensitivity and color tones.

The present invention relates to a polymer composition that includes a polymer having at least one polymer segment represented by the following Formula (I), With reference to Formula (I): M independently for each w is a residue of a monomer; φ is a residue of a mechanochromic compound having at least two reactive groups that are each independently bonded to one monomer residue M; w, independently for each z, is an integer of at least 1; and z is an integer of at least 2. The mechanochromic compound is selected from at least one of the following, (a) a spirooxazine compound represented by the following Formula (II), and (b) an indenonaphthopyran represented by the following Formula (III),

A method for producing a copolymer includes reacting a first monomer with a second monomer using a Pd-based catalyst, wherein the first monomer is a first hetero cyclic compound which includes a first hetero atom selected from S, N, and O, the first hetero cyclic compound in which a carbon atom adjacent to the first hetero atom is coupled with at least one hydrogen atom, and the second monomer is a second hetero cyclic compound which includes a second hetero atom selected from S, N, and O, the second hetero cyclic compound in which the second hetero atom is coupled with a carbon atom in which a halogen group selected from Br, Cl, and I is substituted.

The invention relates to a method for preparation of platinum siloxane compounds containing at least one CO ligand molecule (Pt carbonyl siloxanes). The method comprises reacting gaseous carbon monoxide (CO) with a platinum siloxane compound, preferably a platinum vinyl-cyclosiloxane compound, in solution with an organic solvent. The method is straightforward and applicable to industrial scale. With this method, specific isomers of platinum carbonyl vinylcyclosiloxanes are prepared, in which the two η-2-ethenyl groups coordinated to the Pt atom are bonded in trans-configuration relative to the cyclosiloxane backbone. The Pt compounds obtained by the method are used as catalysts for hydrosilylation and for crosslinking and curing of siloxanes and silanes.

A vehicle barrier system comprises a housing, substantially vertical members, a barrier member, and an actuation assembly. The barrier member is coupled with the substantially vertical members. The barrier member is configured to stop a moving vehicle when the substantially vertical members are in a raised position relative to the housing. The actuation assembly is operable to selectively raise and lower the substantially vertical members relative to the housing to selectively deploy and retract the barrier member relative to the housing. The actuation assembly comprises a powered rotary actuator mounted to the barrier member. The actuation assembly is operable to convert rotary motion from the rotary actuator into linear movement of the barrier member. A counterweight provides opposing mass and vertical motion relative to the barrier member.

A method of constructing a pump island protector to alleviate continuous maintenance required for a deteriorating existing steel pump island base, and a pump island protector constructed by the method. Using an adjustable form system and the combination of stainless steel members and new concrete, the existing pump island is re-wrapped with the stainless steel member and the new concrete.

A road marker and related light based warning device are described. The road marker or device includes a thermal sensor that triggers the illumination of at least one light-emitting diode at a predetermined temperature. The temperature may be associated with ice formation. The light-emitting diode(s) may flash to alert motorists to hazardous road conditions. The road marker or device utilize simple components to increase reliability, particularly when the device is subjected to high heat such as when the device is mounted into hot tar seal. The device further includes a switching element that prevents rapid on/off cycling.

A method of constructing a pump island protector to alleviate continuous maintenance required for a deteriorating existing steel pump island base, and a pump island protector constructed by the method. Using an adjustable form system and the combination of stainless steel members and new concrete, the existing pump island is re-wrapped with the stainless steel member and the new concrete.

An auxiliary member for pavement construction, including: a cylinder, a base plate and a leveling bolt; the cylinder includes a first cylinder part and a second cylinder part which are connected and communicated with each other, the first cylinder part is provided with a sling installing member and a slurry inlet, bottom of the second cylinder part is connected with the base plate, the base plate is provided with a bolt extending hole and multiple slurry discharging holes which are communicated with the inner cavity of the second cylinder part, the leveling bolt includes a bolt head and a screw, the screw extends through the bolt extending hole, the bolt head is arranged in the second cylinder part and the bolt head is smaller than the inner diameter of the second cylinder part. The present invention further provides a concrete slab and a method for pavement construction.

A storm grate locking device and method of use with a lock body. The lock body has at least one hook arm engaged with a latch assembly, a security flange nut engaged with the latch assembly, and a deep well socket. When the lock body is placed into the recessed area of a storm grate; and the hook arm engaged with the latch assembly may be extended to extend under the storm grate thereby preventing removal of the storm grate by rotating the security flange nut.

A surface drainage structure formed above a subgrade may include an elongate drain conduit disposed partially within the subgrade. The elongate drain conduit may define at least one drain slot extending through a wall thereof. The structure may include a pavement layer with an exposed top surface and a drainage channel extending therefrom. The drainage channel may be in fluid communication with the drain slot of the elongate drain conduit. A method of forming the surface drainage structure includes placing the elongate drain conduit in the subgrade, forming the pavement layer, cutting an upper channel along the elongate drain conduit, and cutting a lower channel and the drain slot in the elongate conduit.

A form-fitting connection between two components (5 and 14) has a break-away function in one direction. At least one connection element, designed as a shear bolt (6), is formfittingly connected to the first component (5) to be connected. The end of the shear bolt (6) is formfittingly and functionally connected to a second component (14) via an attached component (17) that is resilient in the direction of the formfitting connection.

A method for repairing an aged or damaged asphalt pavement is provided. The method involves preparing a surface of the aged or damaged asphalt pavement by filling in deviations from a uniform surface plane with dry aggregate and compacting the dry aggregate; applying a reactive asphalt emulsion to the prepared surface; and passing an emitter over the prepared pavement, wherein the emitter generates electromagnetic radiation having a wavelength of from 2-5 mm that penetrates into the pavement to a depth of at least 2 inches. The asphalt pavement is repaired by disturbing voids and interstices in the damaged pavement without dehydrogenation of the asphalt, such that oligomers present in the aged asphalt are linked together into longer polymer chains to improve ductility of the aged asphalt.

A grader blade mounted to a support frame has an auger-grinder mounted ahead of the grader blade. The auger-grinder has a first helical vane fixed to a rotatable axle with a plurality of teeth attached to and protruding outwardly from the auger. A shroud above and partially surrounding the auger-grinder has an inner shroud end wall, an outer shroud end wall and bearings in which the axle is journaled transverse to the direction of travel. A beater is fixed to the axle between an inner end of the helical vane and the inner wall. The beater has a plurality of paddles extending outwardly from the axle. An inner barrier wall is attached to the inner shroud wall and extends forward of the auger-grinder. A drive link is connected to the axle for connection to a prime mover for driving the axle in rotation.

A mobile thermoplastic applicator comprises a kettle, a main gas burner, a heat exchanger plenum, and a screed die box. The kettle has walls which define an interior space for melting thermoplastic. The main gas burner is situated beneath the kettle, and is configured to heat the kettle. The heat exchanger plenum is situated inside the thermoplastic kettle and is configured to subdivide the interior space and circulate heated air from the main gas burner. The screed die box is configured to receive molten thermoplastic from the kettle and deposit that molten thermoplastic on a surface.

A track system may include a plurality of connected slat members that may form rollable tracks. The rollable tracks may be used in moving vehicles across sensitive ground. The rollable track may be deployed using various methods and/or apparatus such as, e.g., deployment apparatus including one or more spool portions for rolling and unrolling the rollable tracks.

A method for laying down a pavement in which a compaction unit such as a tamper pre-compacts the paving material with a selectable stroke and at a selectable frequency while the pavement having a selectable pavement thickness is in the process of being laid down at a selectable paving speed, the stroke of the compaction unit is automatically adjustable in response to paving parameters, such as the paving speed and/or the pavement thickness, along a characteristic curve or in a characteristic map. The compaction unit includes an adjusting mechanism which is operable during the paving operation for adjusting the stroke of the compaction unit.

A vehicle access control system includes an elongate, generally hollow, generally planar base platform having a first and a second distal end. A generally hollow enclosure is atop the base platform. A first lift gate is intermediate the enclosure and the first distal end of the base platform, while a second lift gate is intermediate the enclosure the second distal end of the base platform. A first lift arm is pivotally coupled to the first lift gate and extends generally perpendicularly away from a longitudinal axis of the base platform. Likewise, a second, opposing lift arm is pivotally coupled to the second lift gate and extends generally perpendicularly away from the longitudinal axis of the base platform. The base platform is configured for direct contact with a mounting surface. In addition, the vehicle access control system is transportable as a unit.

A system for converting an existing traffic intersection into an intersection having a roundabout traffic control feature includes a center island framework, one or more splitter island frameworks, and one or more diverter frameworks. The frameworks are secured to the road surface, and fill material is added to free spaces defined in the frameworks to thereby form a center island, one or more splitter islands, and one or more diverters. The system allows a roundabout to be implemented into an existing intersection on a temporary or semi-permanent basis, in a minimal amount of time and without requiring significant construction at the site of the intersection.

A The manhole cover is described with a supporting structure device comprising force distribution ribs for supporting a top surface of the manhole cover which can be driven over, and a hollow force distribution cylinder arranged substantially centrally, in particular a circular force distribution cylinder, for supporting the force distribution ribs, characterised by a force distribution plate to relieve the load on the force distribution cylinder, wherein the force distribution plate at least substantially completely covers an underside of the force distribution cylinder in relation to the top surface, and wherein the force distribution ribs transform smoothly into the force distribution plate.

A manhole cover assembly configured to behave as a relief valve in an explosion event, opening so that fluid, such as air or explosive gas, may vent from an underground area. The manhole cover assembly may include a manhole cover and a frame, and may be configured to limit movement of the manhole cover with respect to the frame in response to increased pressure on the manhole cover. In one embodiment, the manhole cover may include legs that are configured to enable a range of movement of a portion of the cover such that the cover can be unseated at an angle with respect to the frame to allow fluids to escape from the underground area.

A system for measuring the height of paving material distributed by an auger of a paving machine in front of a grading implement, such as a screed, is disclosed. The system includes a sonic sensor and a laser pointer. The sonic sensor generates a sonic signal which is directed at the paving material distributed by the auger. The laser pointer generates a laser beam which is similarly directed at the paving material that has been distributed by the auger. The laser beam and the sonic signal meet at a common position on the paving material.

Disclosed is an automotive road construction machine, particularly a recycler or a cold stripping machine, comprising an engine frame that is supported by a chassis, a working roller which is stationarily or pivotally mounted on the engine frame and is used for machining a ground surface or road surface. The chassis is provided with wheels or tracked running gears which are connected to the engine frame via lifting column and are vertically adjustable relative to the engine frame. Each individually vertically adjustable lifting column is equipped with a device for measuring the actual vertical state of the lifting column.