Metal working – Plural diverse manufacturing apparatus including means for... – Binding or covering and cutting
Reexamination Certificate
1999-04-15
2001-01-30
Briggs, William (Department: 3722)
Metal working
Plural diverse manufacturing apparatus including means for...
Binding or covering and cutting
C029SDIG005, C029SDIG009, C148S334000, C148S334000, C409S134000, C409S164000
Reexamination Certificate
active
06178609
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the field of machine tools and in particular to modifications allowing the changing of parts to be machined while meeting the integration requirements needed more particularly in the use of a machine tool for high speed machining.
2. Discussion of the Background
Usually, the changing device called “palletization” is used for supplying machine tools with parts to be machined: the device brings the part to be machined on the machining tool machining station, the machine tool works the machining range then the machined part to be machined is retrieved and replaced by a new part to be machined for machining.
The known devices called “step by step” are very much adapted for production line machining and to the configuration for machining machine tools for mass production. These machines contain multi-spindle tool heads which ensure the realisation at a very high speed of a range of machining.
These machine tools being subject to constant improvement in speed and precision and due to the fact that more flexible, faster and more precise new mono-spindle machines are appearing, the known devices are difficult to adapt as it is essential in future that they become more flexible, faster and more precise. In fact, the increased flexibility of these machines brings, amongst others, a difference in machining time from one machine to another and the technical procedure of conveying “step by step” cannot be used in such a configuration.
Another constraint to which a changing tool device must now adapt is dry machining. In fact, dry machining, that is to say without liquid projection, does away with the common removal means of chips so that these chips are evacuated with more difficulty and become therefore a more important factor in seizing the components of the machine, of distorsion of the references and of malfunction.
The concept of rotary “palletization” devices in front of each machine and being used as interface between the classical conveying chain of the parts and a high speed machining machine tool, seems to be the best solution to the problem of flexibility. However, a disadvantage of these devices is the high free volume required, at the level of the machining station, by its installation, as the rotation of these devices requires a cylindrical volume of which the base would have for diameter the length of the pallet-changer, taking much more space than a classical palettizer in translatory motion. This disadvantage has often forced the tool office technicians to conceive less space-taking machining assemblies.
The problem of leaktightness, and in particular during dry machining, is more complex for rotary pallet-changers as they bring a pallet in a machining zone by a high speed rotating movement which is difficult to get leaktight, due to the fact that the entire surface of the pallet-changer resting on the machine tool becomes an obstacle at the time of the rotation of said pallet-changer. The leaktightness of existing devices, when it exists, is not always a satisfactory and acceptable compromise in view of the conditions required nowadays for very high speed machining.
SUMMARY OF THE INVENTION
Taking this into account, the Applicant has carried out research on parts changing pallet-changers which has resulted in a new concept of rotary device ensuring the changing of parts to be machined of a machine tool, in the best conditions of leaktighness, speed and space taking.
The rotary device for changing parts to be machined by a machine tool of the invention is of the type of the one constituted by a table which, comprising at least two pallet supports arranged preferably at regular angular intervals to each receive a part-carrying pallet, which is mounted rotating between the machining station of the machine tool and the post for supplying part-carrying pallets arranged opposite the said machining station.
According to the fundamental concept of the invention, such a device is remarkable in that the aforesaid pallet supporting table is mounted on one hand, pivoting about its central axis and on the other hand, tilting between a horizontal position and an inclined position relative to the horizontal plane. This characteristic has the great advantage to move the elements integral with the table, introduced in the machining station, towards the centre of the rotary device in order to free said machining station, to be able to realize the free rotation of the table. The tilting of the plate brings a vertical and horizontal movement of the end of the table introduced in the machining station which allows to sufficiently free the table from the machining station to start a rotation.
According to a particularly advantageous characteristic of the invention, the pallets supporting table of the said device is mounted tilting between the machining station of the machine tool and the supplying station of the part-carrying pallets, about a theoretical horizontal axis arranged orthogonally to the axis alignment of the said stations. Thus, the tilting is effected from bottom to top and from top to bottom, allowing the use of a standard clamping module including references which are used to position the pallets on which the parts are clamped through a classical machining assembly. Another not-unimportant advantage of the tilting of the table of the rotary device for changing the parts of the invention, is to free enough elements linked to the table introduced in the machine tool machining station to ensure their rotation, so that the elements integral with the turning ensemble can rest on the machine.
According to another particularly advantageous characteristic of the invention, the pallets supporting table of the aforesaid device is mounted tilting from its horizontal resting position where a pallet is positioned on the references of the clamping module of the machine tool machining station, to an inclined position above the said clamping module where the pallet is freed of the said references. Furthermore, the rotation movement of the said table is advantageously operated during the inclined position of the said table. Unlike classical “palletization” devices, the tilting of the whole table with pallet has a freeing effect allowing to make it pivot without decreasing the dimensions of the machining assembly ensuring the tightning of the part. Furthermore, in freeing the different elements of the table of the machining station before rotation, the tilting of the table allows to keep the tool magazine essential to the optimal functionning of the machine tool near the machining station without interfering with the rotation movement. Thus, after machining, the table tilts so as to free the part carrying pallet of the references of the clamping module of the tool machine to allow, without impediment, the rotation of the table which positions a new pallet above the references while making the pallet go from the machined part to the loading/unloading station. Once this rotation carried out, the table then goes back into a horizontal position so as to allow the positioning and the clamping of the new pallet and the unloading the old one.
According to another particularly advantageous characteristic, the aforesaid theoretical horizontal axis follows a movement of which the direction is parallel to the vertical plane running through the alignment axis of the said posts. The mobility of this theoretical axis allows to offer an instantaneous centre of rotation to the table so that the freeing of the parts of the machining station can start following a slightly vertical path, which allows the use of all sorts of references on the clamping module. Furthermore, the freeing path can be optimized according to the needs and obstacles, existing and to come, during the rotation of the pallets support table and the tilting can be reduced thanks to the interval of the axis.
Advantageously, the aforesaid theoretical horizontal axis around which the aforesaid table tilts, is situated near the aforesaid supplying post thus allow
Briggs William
Oblon & Spivak, McClelland, Maier & Neustadt P.C.
Renault Automation
LandOfFree
Rotary pallet changer for machine-tool does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Rotary pallet changer for machine-tool, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Rotary pallet changer for machine-tool will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2456491