Abstract: The invention provides a throttle-valve control arrangement for an engine mounted by vibration dampers on a support structure. The arrangement insures that pivotal movements between the engine and the support structure about a pivot center do not effect the throttle-valve setting, by the use of a throttle-valve linkage incorporating a pair of interengaging levers having mutually contacting surfaces, one of which surfaces is curved and has a center of curvature situated on the pivot center between the engine and the support structure.

Abstract: A piston type energy conversion machine in which the thrust of one or more reciprocating pistons is transmitted to a nutating tubular member having longitudinally spaced journal surfaces of revolution about a nutating axis adjustably inclined with respect to a primary engine axis. The journal surfaces on the nutating member are engaged by a crank member rotatable on the primary engine axis and carrying adjustably eccentric bearings to engage the journal surfaces of the nutating member. Angular adjustment of the axis of nutation effects a variable piston stroke distance as a result of a connection of the pistons to the nutating members at points spaced radially from the nutating axis. Compression ratio is adjusted independently by shifting the point of piston connection with the nutating member along the nutating axis.

Abstract: An idler mechanism for maintaining tension on a drive belt of a belt drive system. The idler mechanism includes a pulley mounted to an idler arm for rotation about a rotational axis. The idler arm is attached to mounting apparatus having a resilient and damping element for eliminating vibration and dissipating shock loads on the belt and establishing tension in the belt. In the preferred embodiment the resilient and damping element comprises a torsional bushing having a torsional axis parallel to the pulley rotational axis and a torsional member constructed from a block of resilient elastomeric material which provides both tension and damping.

Abstract: A bicycle sprocket wheel comprises a toothed outer annular member molded of a tough nylon plastic and a centrally disposed metal spider having a plurality of radial arms attached to the sides of the annular member to add structural rigidity thereto. The teeth of the annular member are formed with straight front and back faces and with sharp corners at the roots thereof. Such a construction reduces the cost of the mold used for molding the annular member since the cavity needed therein for the teeth can be simply machined by use of straight and circular cuts. The inner radial edge of the annular member is shaped by an insert in the mold to form sets of circumferentially spaced arcs, the arcs of each set having a common radius different from the other sets to accomodate spiders having arms of different radial lengths.

Abstract: An actuator assembly particularly useful for operating butterfly, ball or plug type valves is disclosed herein and comprises a relatively efficient gear train including first means for coupling the gear train to a drive member and a pinion in driving engagement with a sector gear of limited circumferential extent formed on a periphery, preferably an inner periphery, of a generally triangular sector member. At the vertex of the sector member opposite the sector gear there is provided a rotatably mounted drive member for driving the stem of an associated valve member as it rotates. Accordingly, as the sector gear is driven, the drive member rotates the valve stem to open or close the valve. The input gear train includes a non-reversing coupling means adjacent the first coupling means whereby the drive member can rotate the sector member and, thus, the valve stem, but external forces on the output side of the non-reversing coupling means cannot cause rotation of the valve stem.

Abstract: A transmission for a two-worm press with two counter-running worms, which includes two transmission output shafts respectively connectable to the two counter-running worms, first gears laterally offset relative to each other. These first gears are drivingly interconnected by second gears forming intermediate gears. The transmission also includes a bearing housing detachably connected to a transmission housing which houses axial bearings for the transmission output shafts and also houses the bearings for the intermediate gears. The bearing housing is connected to the worm housing of the two-worm press by means of the rods extending through the transmission housing. One of the transmission output shafts is firmly connected to a first extension shaft so that the latter is rotatable with said one transmission shaft.

Abstract: A four-speed transmission having an over drive is disclosed which comprises two basic planetary gearsets and one dual intermeshed planet pinion planetary gearset and three clutches and two brakes. The construction and arrangement is such that an appropriate reduction ratio is provided for each of forward speeds without causing rotary members between input and output shaft to rotate faster than the input and output shafts.

Abstract: The circular saw blade of the invention is composed of different materials and consists of three concentric zones, -- an inner zone, intermediate zone and an outer zone, -- welded together. The material of the outer zone is a high-speed steel, the outer and intermediate zones are joined together by, for instance, electron beam welding, while the intermediate and inner zones are joined together by a welding method other than electron beam welding.The present invention relates to the saw art, and is concerned with the provision of an improved circular saw blade.

Abstract: A tool for lifting a latch operator of a locked vehicle door which tool is composed of a strip of spring steel bent back upon itself defining a first long operator leg and a second normally diverging shorter latch manipulator leg; the tool is adapted to be inserted, bent end first, between an automobile window and door with the legs in generally parallel relation and pushed downwardly until the upper end of the shorter latch manipulator leg is beneath the latch operator of a locked door and the spring steel will spring outwardly into engagement with the latch operator for lifting it upwardly to unlock it by lifting the longer operator leg and by so doing lifting the shorter leg and with it the latch operator; a string is connected to the end of the shorter leg for pulling it back into generally parallel alignment with the operator leg after the door has been unlocked, so that the tool can be readily removed from the door after it is unlocked.

Abstract: A pipe wrench which is locked in adjustment by engagement of rack-like teeth on the stem portion of the movable jaw with similar teeth on a slidable member carried in a wide groove in a rocking sleeve. The wrench is adjustable with one hand by squeezing the sleeve and slider to disengage the teeth, then moving the jaw stem via a spur engageable with the finger. The major parts of the sleeve and slider may be made of welded steel stampings.

Abstract: A numerically controlled nibbling machine including means for controlling the feed rate of the work piece with respect to the work tool of the machine and in which the feed distance or travel of the work piece is limited by a release time in which the work tool is disengaged from the work piece according to a predetermined number of strokes of the work tool per unit of time. The improvement of the invention comprises the provision of means for determining the release time of the work tool in a single stroke of the work tool for any number of strokes of the tool, and means for automatically determining the minimum accelerations and decelerations of the work piece required for travelling the feed distance and for forming a desired feed rate value for the work piece from the determined release time of the work tool and the feeding distance of the work piece per stroke.

Abstract: Improved dust collector for radial arm saws of the type in which a generally funnel-shaped flat-bottomed shroud is connected to avacuum hose and positioned at the rear of the worktable. The top and bottom of the shroud are contoured so that the shroud partially surrounds the column which supports the radial arm, the bottom of the shroud resting on a platform clipped to the spacer board of the saw table and attached to the saw frame. The shroud is clipped to the platform in a manner permitting it to be aligned with the saw blade, even during bevel cuts along the left half of the saw table, and thus is especially effective in collecting sawdust and wood chips.

Abstract: Apparatus for sawing of curved-form timber feeds the log past a band saw such that the cut follows the curved form of the log. Spaced guides function to guide the log in a curved-form path through the saw. The guides are displaceable in a direction transversely to the feeding direction of the log depending on the curved form of the log. The guides may comprise guide rollers provided on each side of the log to be forced to the sides of the log.

Abstract: A method and apparatus for blanking wide sheet materials into a plurality of pieces of predetermined shapes are disclosed. The apparatus comprises a blanking die press and first and second carriages movable in a predetermined, numerically controlled and programmable sequence along Y and X axes, respectively, relative to the blanking die press. The blanking die includes upper and lower die holders which are adapted to be automatically rotated approximately 180.degree. to reverse the die orientation and thereby more economically blank the sheet material with a minimum of wastage.

Abstract: A guard for preventing the operator's fingers from contacting the sharp edges of a parallel rack of blades in a food slicer, such as a tomato slicer is provided by a set of parallel planar segments intermeshed between and extending slightly in front of the sharp edges of the blades when the pusher is deployed away from the blades in position for introducing the object (tomato) to be sliced between the pusher and blades. A latch, such as a gravity latch, holds the assembly in the open guarded position until the tomato is introduced and the latch is released. In a rotary slicer a small portion of the blades adjacent the pusher are unguarded to facilitate introduction and prescoring of the tomato.

Abstract: A punch and die assembly specifically adapted for use as a parting tool is disclosed. The punch has a working tip of rectangular cross section formed with a radius curved convex shear bottom. The punch mates with the die such that the punch side wall to die side wall clearance is maintained or increased at the corners.

Abstract: In an envelope edge slitter having a base, apparatus for feeding the envelopes one-by-one from the bottom of a stack at an input station to slitter blades in which an endless elastic belt extending around an eccentric pulley has an upper reach disposed in a slot n the base at the input station. The eccentricity of the pulley alternately brings the belt into and out of engagement with the lowermost envelope in the stack while the elasticity of the belt, the eccentricity of the pulley and the speed with which the belt is driven are such as to produce a whipping action of the upper reach of the belt which ensures that adjacent envelopes of the stack are separated and are fed one-by-one to the slitter blades.

Abstract: A keyer circuit for electronic organs and the like in which a single main keyer chip is formed by utilizing large scale integrated MOS technology with the chip adapted for use with organs having different information supplied to the multiplexing system. The chip provides output information to drive discrete circuitry and also has the necessary input for normal multiplexing operation of an electronic organ. The chip according to the present invention provides internal multiplexing for simple organs and standard external multiplexing for more complex organs.

Abstract: The bass note generation system provides one of several different types or styles of bass-line accompaniment for the organist. A chord pattern detector receives signals on keying lines corresponding to keys depressed by the instrument player and attempts to recognize a normalized chord pattern. A counter tracks the operation of the chord pattern detector and provides an output corresponding to the alphabetic note of any recognized chord. If the chord pattern is recognized, the output of the detector and the output of the counter address a normalized and preprogrammed bassline pattern memory. The digital value of the bass note stored in the memory and the outut of the counter are serially added to transpose the normalized bass note to the appropriate musical key and applied to a decorder-keyer circuit at selected time intervals in a musical measure for providing a precomposed musical bassline output.

Abstract: An amplitude curve generator for use with an electronic organ or the like to control the musical shape of an audible tone. The generator utilizes a simple binary down counter driven from a clock source to produce a sequence of decreasing binary numbers that approximate the relative amplitudes of equally spaced points along an exponential decay curve. The count condition of the least significant bits of the counter correspond to the mantissa of number expressed in binary floating point notation. The most significant bits represent the power. The bits of the mantissa are transferred to a parallel shift circuit and shifted a number of times determined by the bits of the power to convert the number in the counter to fixed point notation. The output of the shift circuit is used to control the envelope amplitude of a musical tone. The output may be subtracted from one (2's complement) to produce a set of values that correspond to an exponential attack curve rather than a decay curve.

Abstract: A choral generator is formed from a plurality of delay channels, each including a modulated delay line which non-linearly varies the time delay imparted to a signal passing through it. The outputs of the delay channels are combined with the undelayed audio signal to form a composite output characterized by enhanced musical presence.

Abstract: Music box of the rotatable drum type with removable reed actuating pins which may be selectively disposed for playing various compositions, characterized by a drum having a peripheral surface without apertures therein and an envelope or sleeve surrounding same containing the apertures for retaining the pins, the envelope being injection moulded of plastic material, the apertures being non-circular, such as square, and the pins being cylindrical and of uniform diameter at all sections thereof.

Abstract: A piano plate is provided, preferably on the top surface thereof, with a fine rugged pattern comprised of a number of shallow recesses of various shapes and dimensions for betterment of its resonance characteristics responding to vibrations of a wide variety of frequencies, particularly to vibrations in the treble range, and, when required, for enrichment of aesthetic effect. The vacuum process is advantageously used for manufacturing thereof thanks to its smooth flow of molten metal at casting and easy removal of the cast product from the associated mold.

Abstract: Described is a stringed instrument construction, particularly a guitar construction, including a seamless, hollow, one piece body portion or sound box molded from a synthetic material. The body can be molded by conventional spin or roto casting techniques. The body portion or sound box is acoustic and can therefore be used for either an electric type instrument or a conventional manual or acoustic type instrument. A neck construction is also described comprising a metal and hardwood laminate which does not allow any significant deflection due to string load.

Abstract: A device for securing a harness to a musical instrument such as a guitar is provided with a receptacle assembly on the musical instrument and a pin member attached to a harness. Means selectively engage a projecting portion of the pin member within a chamber of the receptacle assembly and allow for rotatable movement therebetween.

Abstract: A threaded fastener incorporates a long-pitch helical thread rolled on a cylindrical blank of predetermined diameter, leaving untouched a section of the blank between adjacent turns or convolutions of the thread. The thread has a crest which is greater in diameter than the blank and a root which is smaller in diameter than the blank. The contour of the thread in a plane including the longitudinal axis of the screw is unsymmetrical about a line perpendicular to the axis and passing through the crest, the flank of the crest facing the head end of the screw being more nearly perpendicular to the axis than the flank facing the work-entering end of the screw. At each juncture between the root of the thread and the adjacent untouched blank sections, there is an outwardly extending helical bur or crest which functions as an auxiliary thread to improve the holding power of the screw.

Abstract: An expansion dowel assembly includes a sleeve, a tie rod insertable into the sleeve, an expanding body connected to one end of the tie rod and an end support on its other end. A member is connected to the end support for transmitting torque to it and by virtue of the torque applied to the end support the expanding body is drawn into the sleeve causing it to expand. Shear pins connect the member to the end support and when a predetermined torque is reached the pins shear off and the member can be removed from the end support. The shear pins can be arranged either parallel or perpendicular to the axis of the tie rod.

Abstract: An improved low-profile turret for a large-calibre tank-mounted firearm includes a support for operating personnel and a box-shaped structure which permits the turret to blend into the upper surface of the tank. An improved loading pendulum is also disclosed.

Abstract: A fluid pressure unit with a cylinder block is provided with radial bores of rectangular cross section. Pistons are disposed in the bores, each of the pistons being provided with a piston cap which is subjected periodically to pressure of a medium and with a roller resting against the piston cap. A cam is provided around the cylinder block, upon which the respective rollers rest. Each roller defines a variable throttle space with a first side wall of a respective one of the radial bores, which wall is vertical with respect to the rotational direction. The piston cap forms a sealing point with at least a second of two side walls.

Abstract: The hydraulic motor has a shaft rotatably mounted in a housing and mounting an eccentric to which is journaled an annular ring. A plurality of radial pistons are adapted for sliding movement within spherical members having cylindrical bores for receiving the radial pistons. Each of the spherical members is adapted for oscillating movement between an annular abutment and a spring-mounted annular ring-type valve seat.The ring acts as a distributor sleeve or and as a conduit for fluid passing to and from the cylinders and a planar distributor.The hydraulic motor can be used either as a pump or a motor at low or high speeds and under high pressures and is reversible.

Abstract: Flat open carton blanks are fed by a conveyor past two rotating plows located on each side of the conveyor. A first plow is located upstream of the second plow, and a glue applicator is located in a position to apply glue to one edge of the blank. A stationary plow or wedge is located ahead of each rotating plow. As the blank is advanced, a first panel is folded upon the blank by the first rotating plow. Glue is applied to the edge of the first panel. As the blank is conveyed past the second rotating plow, a panel on the opposite side of the blank is folded upon the blank with its edge in contact with the glue applied to the edge of the first panel. The thus folded blank is passed through the nip of press rolls to press the two glued edges together. A diverter is provided to reject double folded blanks.Upstream of the first plow are at least two sets of creasing rolls which back-break at least two preformed score lines in the blank to facilitate opening of the glued blank on a cartoner.

Abstract: A method and apparatus for increasing the safety and productivity of tunnel workers active in high pressure environments is disclosed. The workers are housed at an intermediate pressure over a "work week" of at least several days and are transported between the tunnel face and the life support chamber in which the workers are housed in a pressurized personnel transport chamber. The housing contains sanitary, sleeping, decompression, storage and dining facilities and is generally located at the tunnel entrance. In the preferred embodiment, the intermediate pressure is about half of the tunnel working pressure but not more than about 20 psig and preferably less than 17 psig. It is expected that a decreased incidence of bone related diseases and bends will result due to the reduced number of full decompressions from the tunnel work environment.

Abstract: A system for the protection of a building, house, or like structure, is provided which affords protection against the forces of wind, pressure differentials, water and sound. The device features a ventilation system which allows normal ventilation of the structure, but provides an increased area through which air can travel in the event of a tornado or like storm which produces a rapid and large change in atmospheric pressure. There is additionally provided a wind deflecting side portion which remains in a normally open position, which open position absorbs and deflects the force of high velocity winds as is generated by hurricanes and the like. Water protection is provided by drains and deflecting anti-splash plates that prevent the entry of excessive amounts of water into the inner portion of the structure. Within the structure, louvers through inner walls equalize pressure between different rooms, lessening the chance for pressure differential change.

Abstract: A passenger-space ventilation system for motor vehicles, especially for passenger motor vehicles, in which the used-up passenger-space exhaust air, after its discharge out of the passenger space but prior to its discharge into the outside air stream flowing about the vehicle, is conducted past heated-up vehicle parts for purposes of cooling the same.

Abstract: In a milk processing system wherein heat treated milk is initially separated into high-fat and low-fat milk and subsequently reconstituted by adding a selected proportion of high-fat milk to the low-fat milk, control means are provided for automatically controlling the proportion of high-fat milk mixed with the low-fat milk to provide a milk blend of standardized butterfat content which is then homogenized. The control means includes a photoelectric monitoring system for continuously measuring the butterfat content of a sample of the homogenized milk as the latter flows continuously through the processing system under pressure of the homogenizer in the system. The butterfat content measurement is converted to digital signals which are compared to a pre-set digital signal corresponding to a desired butterfat content level to produce a digital corrective signal which controls a digital valve regulating the proportion of high-fat milk blended with the low-fat milk in the processing system.

Abstract: A nut huller and/or sheller comprising, in combination, a container with its long axis vertical, a rotatable shaft concentrically mounted within said container, a plurality of radially extending blades mounted on said shaft to form a rotor assembly, said blades being divided into an upper group attached to an upper portion of said shaft in a helix of one direction and a lower group attached to a lower portion of said shaft in a helix of the opposite direction, a means for journaling said shaft in said container, and a means for rotating said rotor assembly.

Abstract: A horizontal piston-type compactor is mounted in a housing, having an open end, that is diagonally joinable to a trash container, also having an open end, the open ends coinciding in horizontal alignment to form the unit. A trash receiving port, surrounded by a combing, is defined in the top of the housing and overhangs the bottom of the trash container owing to diagonal joint between the housing and the container, to provide an interior spillage area and use of higher trash compacting pressure in the container. Side liners are pivoted to the respective sides of the container adjacent its open end and extend oppositely therefrom short of an opposite closed end thereof.

Abstract: There is disclosed a device for dewatering sludge such as residuals in sewage discharge processing installations. The device provides that cakes are formed of the sludge. These cakes have initially a high water content and are of non-homogenous, loose consistency. They are guided between filter bands through a preliminary filtering zone in which some of the water contained in the cakes is extracted by straining and pressure action applied thereto. The filter bands with the cakes therebetween are then successively guided over a first dewatering drum and a subsequent second dewatering drum. Pressure is applied to the filter band while being guided about the drums, thereby extracting further water from the cakes. Additionally, the cakes while traveling from the feed-in point toward and through pressure zones are deformed and also turned over thereby compacting the cakes as water is extracted therefrom. Finally, the cakes after being sufficiently dewatered and compressed are discharged.

Abstract: An electrophotographic print marking apparatus for printing markings on rolled steel plates while the steel plates are being fed in a heated condition. A part of an image transfer belt which is brought to a transfer section where the powder image carried by the belt is transferred to the steel plate is made movable up and down by means of a pair of lower rollers. The rollers are moved up and down to bring the part of the belt in the transfer section close the steel plates when the powder image is transferred to the steel plates and to separate the belt far apart from the steel plates when the powder image is not transferred. A tension roller is provided to absorb the change in tension of the transfer belt accompanying the up and down movement of the lower rollers.

Abstract: A code imprinting plate device for use along with the print heads of a portable labeling machine: the code plate device includes a casing that is removably retained in position on the frame of the printing device of the labeling machine, an imprinting code plate having type characters on it and adapted to be inserted into and removed from the casing, a sliding assembly which is slidable in the casing in response to the insertion and removal of the code plate; engagement and disengagement means are brought into and out of engagement with the sliding assembly so as to hold that assembly in position; the code plate is retained in position in the casing, whereby the label can be imprinted with the type characters on the code plate in addition to those on the other heads of the printing device.

Abstract: A portable label printing and dispensing machine which includes: a printing device fixed to the machine frame; a movable platen positioned under the printing device; a spring held against exerting a biasing force; means to release the spring to push up the platen to strike against the printing device; and a push back means to separate the platen from the printing device just after printing.

Abstract: A form roller compensator is provided for use in mounting a printing form roller in a publication printing apparatus in proper orientation relative to a printing cylinder. The form rollers in a printing machine control the amount of ink transferred to the printing surfaces of a printing cylinder for printing alphabetic and numerical characters and pictorial illustrations. The invention allows the amount of ink transferred by printing form rollers to be varied to compensate for the inordinately heavy or light supply of ink which results from pressure variations of the form rollers against impression cylinders. These pressure variations are caused by thermal expansion or contraction of the various rotating cylinders involved.

Abstract: For fitting a printing sleeve in a printing roll the outer surface of the roll core and preferably the inner surface of the sleeve are made with one end of a lesser diameter than the other; the sleeve is slightly undersize diametrically. Remote from the ends of the core are orifices whereby gas under pressure may be blown radially outwardly from the core. The difference in diameter allows the sleeve to be passed freely along the core until it jams up against an increased diameter portion of the outer surface of the roll, at which time it covers the orifices. Gas is then blown from the orifices to expand the sleeve which can then be moved into its working position on the core. A sleeve specially suitable for this treatment is made by laying-up a seamless GRP layer on a former which is undersize for the designed core and either curing a rubber layer in situ onto the layer, or adhesively securing a flexible plate to a true cylindrical outer surface of the GRP layer.

Abstract: For fitting a printing sleeve in a printing roll the outer surface of the roll core and preferably the inner surface of the sleeve are made at least partly tapered; the sleeve is slightly undersize diametrically. Remote from the ends of the core are orifices whereby gas under pressure may be blown radially outwardly from the core. The tapers allow the sleeve to be passed freely along the core until it jams up against an increased diameter portion of the tapered outer surface of the roll, at which time it covers the orifices. Gas is then blown from the orifices to expand the sleeve which can then be moved into its working position on the core. A sleeve specially suitable for this treatment is made by laying-up a seamless GRP layer on a former which is undersize for the designed core and either curing a rubber layer in situ onto the layer, or adhesively securing a flexible plate to a true cylindrical outer surface of the GRP layer.

Abstract: A reliable delay detonator device is disclosed which is thermally and chemically stable and which is also insensitive to mechanical shock and electrostatic charge. The device can be made with differing time delays and can be interconnected with other detonator devices for achieving multiple delay characteristics. A modification of the device is particularly suited to high temperature use. None of the devices contain any primary explosives, the device relying upon pyrotechnic delay materials and secondary explosives.

Abstract: A system permitting VT (Variable Time) fuze setting information to be transmitted thereto from a remote fire control source via a microwave link when the fuze is chambered in a gun barrel prior to the firing of an artillery shell to which the fuze is affixed. Sufficient microwave power is initially transmitted to the fuze by means of the barrel acting as a microwave transmission line wherein the microwave power received is converted to a DC voltage which is stored and used to bias the fuze circuitry which subsequently receives binary detonating data AM modulated on a microwave carrier.

Abstract: A missile security mechanism comprises a sliding rod having two axially spaced-apart grooves, a socket slidably mounted on the rod and having hooks able to engage in one of these grooves then the other, and an inertia-block in the form of a sleeve surrounding and locking the hooks in the groove in which they are engaged. The inertia-block is displaceable by inertia against the action of a biasing spring to free the hooks. A second spring biases the rod towards the socket, the rod being held by a pawl which is movable to free the rod in response to a given displacement of the inertia-block.

Abstract: A trolley conveyor comprising a hollow guide rail within which an endless conveyor chain is centrally supported by guide rollers. A plurality of spaced U-shaped hangers supported by said chain extend through a longitudinal opening in one side of the guide rail spaced above the bottom of the rail. The lower side of the guide rail below the opening is inclined outwardly and serves to contain foreign matter present within the guide rail as well as to catch matter falling from above. The hangers each include a projection adjacent the longitudinal opening which serves to prevent the splashing of foreign matter from the interior of the guide rail out through the opening.

Abstract: An apparatus is disclosed for lagging (in-process storing) packages of textile yarn on wheeled buggies. At least one storage lane for textile yarn buggies is provided and a plurality of wheeled textile yarn buggies with connecting hooks having depending tail portions for joining the buggies together as a train are positioned in the storage lane. Air switch pads are provided at the exit from the storage lane for detecting the presence of a buggy. A driven chain with lugs thereon for moving the train of buggies forward one buggy length and then engaging the depending portion of the hooks for disconnecting the buggy nearest the exit from the remainder of the train is actuated by a signal from the air switch pads each time the air switch pads fail to detect the presence of a buggy.

Abstract: Railway rolling-stock truck bolster or cross-member provided with a bearing for receiving the vertical pintle of the vehicle, wherein at least one of a first pair of front and rear sectors of the upper edge of the bearing, facing the front and rear end of the vehicle, respectively, is substantially tangent, in a central area, to the upper edge of a corresponding lateral wall portion of the cross member, at least one of the sectors of the first front and rear sectors of the upper edge of the bearing is connected via a pair of skew surface portions each beginning in each one of two lateral portions of said sector to a pair of inclined lateral surfaces of the cross member.