as shown in fig1 and 2 , the machine in accordance with the invention includes a supporting structure ( 1 ). the latter consists of a girder ( 2 ) which bears at its forward end a three - point coupling arrangement ( 3 ) for connection to a drive tractor which is not shown . the other end of the girder ( 2 ) carries a rotor ( 4 ) which is used to swath products such as cut grass lying on the ground . said rotor ( 4 ) has a box or case ( 5 ) mounted so as to be able to turn about an approximately vertical support axle ( 6 ). this support axle ( 6 ) is secured at its upper end in a bearing of a protective cap ( 7 ) which is itself attached to the girder ( 2 ). inside this protective cap ( 7 ) there is a toothed crown ( 8 ) which is solidly attached to the box ( 5 ), e . g ., with screws . in the part of the protective cap ( 7 ) which is directed toward the girder ( 2 ) there is a transmission shaft ( 9 ) having a pinion ( 10 ) which meshes with the toothed crown ( 8 ). this transmission shaft ( 9 ) can be connected to the tractor power take - off shaft by means of intermediate shafts ( 11 ) for the purpose of driving box ( 5 ) of the rotor ( 4 ) in rotation . the box ( 5 ) is provided with bearings ( 12 ) through which arms ( 13 ) pass . the latter extend in the form of spokes and bear at their outer ends work tools ( 14 ) such as forks . the arms are housed in said bearings ( 12 ) in such a manner that they can turn about their longitudinal axes . on the part of the support axle ( 6 ) located in the casing ( 5 ) is mounted a fixed cam ( 15 ) which is intended to control the tool - carrying arms ( 13 ) during operation . for this purpose each arm ( 13 ) has at its end , which extends inside the casing ( 5 ), a lever ( 16 ) with a roller wheel ( 17 ) which is guided into a groove ( 18 ) of the cam ( 15 ). the guidance of each roller wheel in its groove causes the rotation of the respective arm about its longitudinal axis . the lower end of the support axle ( 6 ) is located under the casing ( 5 ). a girder ( 19 ) or a similar piece is attached to this end of the support axle by means of screws or bolts ( 20 ). this girder ( 19 ) is directed in the direction ( a ) of advance of the machine . it has a rectangular shape and is preferably hollow . this girder includes one approximately vertical pivot spindle ( 21 ). this pivot spindle ( 21 ) is housed in a tube ( 22 ) which is solidly attached to the girder ( 19 ). it is located in front of the support axle ( 6 ) of the rotor ( 4 ), approximately in a same plane ( p ) which is directed in the direction ( a ) of advance . a support ( 23 ) is articulated on the pivot spindle ( 21 ) in such a manner as to be able to turn in an approximately horizontal plane . this support ( 23 ) consists of a curved tube ( 24 ) and two approximately horizontal plates ( 25 and 26 ) which are soldered to said tube ( 24 ). these plates ( 25 and 26 ) are located one above the other on either side of the girder ( 19 ). each one includes an opening ( 39 , 40 ) through which the pivot spindle ( 21 ) passes . the latter is provided with a clip ( 49 ) which allows one to attach it to the plate ( 26 ). each end of the tube ( 24 ) has an approximately horizontal articulation axle ( 27 , 28 ). on each of these axles ( 27 and 28 ) is mounted a beam ( 29 , 30 ) with two carrying wheels ( 31 and 32 , 33 and 34 ) which are offset with respect to one another in the direction ( a ) of advance and are located under the rotor ( 4 ). each of these carrying wheels ( 31 to 34 ) turns on a spindle ( 35 to 38 ) arranged near one of the ends of the respective beams ( 29 and 30 ). the two spindles ( 35 and 36 or 37 and 38 ) of the same beam ( 29 or 30 ) are located at approximately equal distances from the corresponding articulation axle ( 27 or 28 ). the pivot spindle ( 21 ) of the support ( 23 ) on the girder ( 19 ) is located in front of a line ( l ) which passes through the spindles ( 35 and 37 ) of the most forward wheels ( 31 and 33 ) of the two beams ( 29 and 30 ). the girder ( 19 ) includes on each of its lateral sides a stop piece ( 41 , 42 ) to limit the displacements of the support ( 23 ) about the pivot spindle ( 21 ). for this purpose each branch of the tube ( 24 ) includes a blocking clip ( 43 , 44 ) which is directed toward one of said stops ( 41 and 42 ) and which can engage one of the stops when the angular displacement of the support ( 23 ) is a maximum . the girder ( 19 ) includes an abutment ( 45 ) against which the support ( 23 ) rests when the machine is resting on the wheels ( 31 to 34 ). this abutment ( 45 ) is located between the approximately vertical pivot spindle ( 21 ) and the support axle ( 6 ) of the rotor ( 4 ). it consists of a buffer ( 46 ) made of plastic . this buffer ( 46 ) is inserted in a tube ( 47 ) which is approximately vertical and solidly attached to the girder ( 19 ). the position of the buffer ( 46 ) in the tube ( 47 ) is adjustable by means of a screw ( 48 ) which pushes on its upper end . it can thereby be displaced downward until it comes in contact with the plate ( 26 ) of the support ( 23 ). because it is made of plastic this improves sliding on said plate ( 26 ). the articulation axles ( 27 and 28 ) of the beams ( 29 and 30 ) can be displaced heightwise on the tube ( 24 ) of the support ( 23 ). this allows one to vary the spacing of the rotor ( 4 ) with respect to the ground . the invention also pertains to a machine with two rotors ( 4 ) such as described previously . in this case the rotors ( 4 ) are arranged on the sides of a common carrying structure . during operation , the machine according to fig1 and 2 is displaced on the ground in the direction ( a ) of advance by means of a tractor to which coupling arrangement ( 3 ) is connected . the rotor ( 4 ) is then driven to rotate in the direction ( f ) about the support axle ( 6 ) by the power take - off shaft of said tractor . during this rotation the cam ( 15 ) controls the tool - carrying arms ( 13 ), through the intermediary of levers ( 16 ) and roller wheels ( 17 ), so that they displace their tools ( 14 ). thus , on the forward part of their trajectory these tools ( 14 ) are approximately vertical and pick up the products lying on the ground . subsequently , on the lateral part of their trajectory , the tools ( 14 ) are raised so that they deposit the gathered products in the form of a swath . finally , said tools ( 14 ) return gradually to the gathering position on the rear part of their trajectory . during this operation the wheels ( 31 to 34 ) roll over the ground and support the rotor ( 4 ). when they pass over uneven places they pivot with the corresponding beam ( 29 or 30 ) about the articulation axle ( 27 or 28 ) of the latter . the height displacements of the wheels ( 31 to 34 ) are then greater than displacements of the corresponding beam ( 29 , 30 ) at the level of its articulation axle ( 27 , 28 ). for this reason the displacements of the rotor ( 4 ) are smaller . the latter is then more stable and can move forward at greater speed . 0n the other hand , at curves and turns of the trajectory followed by the tractor and the machine , all of the carrying wheels ( 31 to 34 ) pivot together with their beams ( 29 and 30 ) and the support ( 23 ) around the approximately vertical pivot spindle ( 21 ) of the latter . said wheels ( 31 to 34 ) therefore orient together , without skidding , in the direction ( a ) of advance . they are no longer able to deviate separately from their trajectory . the pivoting movements about the pivot spindle ( 21 ) are limited by means of the stops ( 41 and 42 ), especially in order to prevent the carrying wheels ( 31 to 34 ) from entering the trajectory of the tools ( 14 ). when the carrying wheels ( 31 to 34 ) of the machine rest on the ground , the support ( 23 ) leans against the abutment ( 45 ) of the girder ( 19 ). for this reason , stresses on the pivot spindle ( 21 ) are relieved and the rigidity of the support ( 23 ) is improved . in the case where the machine includes two rotors ( 4 ), the carrying wheels provided under the latter orient in the same manner as those already described . it is quite evident that the invention is not limited to the method of implementation as described previously and shown in the attached drawings . some modifications are possible , especially pertaining to the make - up of the different elements or by substitution of engineering equivalents , without , however , departing from the protected scope of the invention .
a hay making machine including a carrying structure which can be attached to a tractor such that the carrying structure can travel with the tractor in a forward direction . a substantially vertical support axle is mounted to the carrying structure and supports a rotor having hay making tools . a girder is attached to the support axle . a support structure is articulated to the girder via one substantially vertical pivot spindle positioned forward of the support axle . two beams , each carrying two carrying wheels , are connected to the support at opposite sides . at curves and turns of the trajectory of the tractor , all of the carrying wheels will pivot together with their beams and the support structure around the pivot spindle . the wheels will therefore be oriented together , without skidding , in the forward direction .