Turning – Lathe – With work feeder or remover
Reexamination Certificate
2000-05-10
2001-11-06
Tsai, Henry (Department: 3722)
Turning
Lathe
With work feeder or remover
C082S125000, C082S162000, C082S167000
Reexamination Certificate
active
06311592
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention concerns a loader for sprocket wheels, and also the method to automatically position double-toothing sprocket wheels which use the loader, as set forth in the respective main claims.
The invention is used in machines to produce single-toothing or double-toothing sprocket wheels generated by cutting blades or pinion instruments.
The invention may cooperate with centering devices employed in the case of sprocket wheels with double, straight or bi-helical toothing, wherein the second ring is produced in a subsequent step to the production of the first ring.
The invention is used to carry the pieces to be worked, automatically and in sequence, into correspondence with the operating station of the pinion instrument and subsequently to discharge the completed sprocket wheels from this station, at the same time positioning a new piece to be worked.
The state of the art covers positioning and centering assemblies employed in the production of sprocket wheels; such assemblies substantially comprise a supporting base cooperating with a shaft for the axial positioning and clamping of the piece, and are associated with a pinion instrument acting peripherally to the piece to form teeth thereon.
The unrefined piece is arranged on the supporting base on which it is then made to rotate, while the shaft clamps it in position.
While the piece is rotating the pinion instrument works the piece, rotating and moving alternately and in coordination with the rotation of the supporting base.
In order to work the pieces the worker must load the piece each time onto the supporting base at the beginning of the operation and must remove the piece when the work has been concluded.
These loading and unloading operations considerably slow down the production cycle; it must also be considered that a single worker has to look after two or more machines, and therefore the efficiency of these machines is considerably reduced.
In the production of double-toothing sprocket wheels, or sprocket wheels comprising two rings of teeth which are symmetrical to the median transverse plane of the piece, the worker is obliged to further position the piece in the course of his work since the two rings are made in two different steps and normally on two different machines.
When the second ring has to be made, the piece has to be angularly positioned with extreme precision with respect to the pinion instrument in order to obtain the desired, accurate reciprocal positioning between the teeth of the two rings.
This involves a further lengthening of the working times, with a consequent slow down of the production cycle, a reduction in the efficiency of the machines and an increase in production costs.
WO 88/05364 describes a rotary loader for pieces to be machine-worked, which comprises seatings, open towards the outside, wherein the piece is inserted.
These seatings are delimited by clamping elements, for example wedge-shaped, screwed to the body of the loader and which act under pressure on the side of the piece to be worked.
This kind of loader entails long, complex operations to insert the piece and adapt the size of the seating, which require the wedge-shaped elements to be disassembled.
Moreover, the range of sizes and shapes of the pieces which can be worked is very limited, inasmuch as it is not possible to vary by much the size and the shape of the seating, except by using differentiated clamping elements for every size of piece.
Furthermore, in the housing seatings the pieces to be worked are, for a substantial portion, arranged outside the seating, which can cause knocks or damage during the complete rotation of the loader.
The present applicants have designed, tested and embodied this invention to overcome the shortcomings of the state of the art and to achieve further advantages.
SUMMARY OF THE INVENTION
The invention is set forth and characterised in the respective main claims, while the dependent claims describe other characteristics of the idea of the main embodiment.
The purpose of the invention is to achieve a loader for sprocket wheels which will allow the pieces which have been worked or still have to be worked to be positioned in/removed from the operating zone quickly and automatically.
Another purpose of the invention is to limit the inactivity of the pinion instrument between two successive operations, limiting manual intervention to a minimum, reducing dead times of the working cycle, increasing the efficiency of the machines and reducing production costs.
A further purpose is to obtain an automatic positioning method, when working with double-toothing sprocket wheels and cooperating with a centering device, which will ensure the precise angular positioning of the piece in order to begin making the second ring.
The loader according to the invention may be associated with an assembly to position and center the pieces which form the sprocket wheels, and cooperates with the supporting base.
The loader comprises a turntable element which has on its periphery a plurality of housing seatings suitable to contain the pieces which are to be worked in order to form the sprocket wheels.
According to a variant, the turntable is defined by a rotary ring or by a conveyor belt including the plurality of seatings on its periphery.
Each housing seating has at least a front-aperture of a size mating with the size of the pinion instrument, so that the pinion instrument can work without coming into contact with the loader.
According to a variant, the housing seatings are slightly wider than the diameter of the piece to be worked so as to determine a desired play between the housing seating and the relative piece.
According to another variant, the housing seatings have a width which is variable and/or can be adjusted to allow pieces of a different diameter to be housed therein.
According to another variant, the turntable element cooperates with an underlying sliding support and the pieces to be worked, arranged inside the housing seatings, lie thereon.
At the beginning of the cycle, the pieces to be worked are arranged in the housing seatings of the turntable element; the latter is then made to rotate until it places a first piece in correspondence with the operating station of the pinion instrument; once the piece is centered and clamped onto the supporting base, work thereon begins according to conventional methods, with a rotation of the piece-bearing table and the sequential formation of the teeth.
It is possible to perform this work thanks to the presence of the front aperture of the housing seating, which allows the pinion instrument to be inserted onto the piece which is to be worked.
When this operation is complete, the piece is freed from the grip of the machine and the turntable element is rotated once more, the sprocket wheel which has just been formed is discharged from the operating station and at the same time a new piece is brought into correspondence with the operating station.
While the other piece is being worked, the first sprocket wheel can be removed from the relative housing seating and replaced by a new piece which is to be worked.
According to the invention, in the case of a double-toothing wheel, the loader cooperates with centering means, rotationally solid with the piece-bearing table, suitable to automatically position in a correct manner the piece being worked with respect to the pinion instrument in order to make the second ring of teeth according to the desired reciprocal angular positioning of the teeth of the two rings.
According to this embodiment, the centering means, which can be in any circumferential point whatsoever with respect to the piece which has just been worked, are rotated through a desired arc, after the completed piece has been discharged, by means of rotating the piece-bearing table.
This rotation is used to carry the centering means into alignment with the straight line orthogonal to the inner and outer lines tangent to the ideal position of the piece to be worked on the piece-bearing table.
In the case of a circular loader, with an
Akin Gump Strauss Hauer & Feld L.L.P.
Technologies Research Holding S.A.
Tsai Henry
LandOfFree
Loader for sprocket wheels and method to automatically... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Loader for sprocket wheels and method to automatically..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Loader for sprocket wheels and method to automatically... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2606271