IMPROVED GILL BOXES WITH ROTATING HEADS

Abstract: The invention concerns an improved gill box with rotating heads, which comprises a plurality of needles acting on an assemblage of slivers fed substantially continuously and consists of a feeder group (59-60-61), a group which controls the fibres and is constituted by two heads with combs (20-21) superimposed one above the other and rotating in cooperation, and a drawing group (54-55-58). Said gill box can comprise in reciprocal cooperation and co-ordination at least part of the following improvements: opposed rotating means (17) to guide (15-30) the ends (23) of the combs (22): stationary guide-cam means (27-28) cooper­ ating in an intermediate position between the needle field (24) and said rotating guide means (17): means (36-38) to lubricate said rotating guides (16-30): means to feed (32-34) and convey (35) fluid under pressure into the zone of the outgoing sliver (44-45) and inside every needle field (24): means (46-47) to ensure a differentiated path of insertion of the needles (29) into the sliver: means (44-45-16-30-22) for a perpendicular and non-interfering withdrawal of the needles (29) from the sliver: means (48-49) for individual protrusion of the combs (22) for better cleaning (62) of the needles (29): pulling means (17-18-19) always in phase with said rotating guide means (17): means (17-18-19) to reduce angular play: means (54-55) to reduce the distance travelled by the outgoing sliver.

Description: Description of the invention entitled: Improved gill boxes with rotating heads. in the name of OFF. SAVIO S.p.A. submitted on under No. This invention concerns gill boxes with rotating heads; to be more specific, the invention refers to improved gill boxes with rotating heads comprising a plurality of innovat -ions which have a very great effect on every characteristic. -of the gill box itself0 Gill boxes are knovn which are of a type that includes. -at least one pair of rotating heads which pull into rotation along a pre-set course a plurality of needles acting on an -assemblage of slivers fed substantially continuously. Said -needles penetrate into the slivers in an interlaced position so as to carry out the combing and drawing phase. The invention concerns such a type of gill box with rot -ating combs as is composed substantially of:- a feeder group of at least two rollers, one lower roller and one upper pr -Ssure roller, said group having the task of feeding the plur -ality of slivers coming from the creel or from a preceding treatment station up to the apparatus comprising the pair of heads with rotatinG combs: a group to control the fibres -which consists of a pair of heads with combs, said heads being superimposed one above the othcr and rotating in opposite directions and having respectively a plurality of needles protruding from said heads: and a drawing group consisting of a -pair of twin roll.ers together ?dth an upper pressure roller. and having the task of nipping the fibres and withdrawing . them from the slivers controlled by the needles of the combing head. The operation carried out on the slivers passing through is called the drawing operation and, as its outcome, the fibres are made parallel and the sliver itself is improved. . Many proposals for such types of gill boxes are known. Patent DE 72717 - MEUNIER - proposes a gill box with only one plurality of needle bars running radially along slots envisa- ged at the ends of the bars and forming part of to motive . heels, being positioned as desired by two inner cams and an outer steel band. The system in itself is sound, but it is not possible to understand it thoroughly, for it is inpossible to judge how. such a device can work at high speeds or even just for a merely suitable time. Indeed, it is necessary to bear in mind that the resistance spring cannot work at the high frequencies generated by the successive blows of the needle bars which will take place at the high rotation speed of the grooved disks. . Moreover, the inner countercam system is hard to realize because it tends of necessity to rotate, and we are not shown how it is expected to clanp it, nor is it even indicated how the grooved disk can rotate. . Furthermore the system in itself is just sketched out and not capable of being applied in practice. Patent DE 259689 - BOUbRY - proposes a device like that of DE 727T7 but with a different path for the needles. Our remarks concerning DE 727I7 are applicable to this patent -too. - Besides, the countercam is not indicated, and therefore -it is impossible to understand how the combs can be kept with -in the course envisaged in the lower cam. Furthermore, vle cannot understand which are the movable arts and which are the stationary ones; moreover, according to the grooves as shown, the device carrot function. Patent GB 431.984 - ATELIERS SAINT ELGI - proposes a system of rotating needles of which the carrying bars coop erate with cranks and circular cams. The same patent proposes a solution with a chain and with two series of needles side by side and a so-called 'intersecting solution, since it envisages two systems of rotating needles, one superimposed on the other, between which -the sliver to be treated passes. - This patent envisages that the needles follow a substantially circular course, and this results in a limited comb-. -ing effect as regards action, duration and results. For this reason the patent visualizes the two heads side by side and the chain system. . Furthermore, the crank system cooperating with inter .secting cams imposes rather a low maximum speed of rotation, - Moreover, the number of rows of needles which this pa-, .tent allows is rather small, and the outcome is that only very long fibres can be processed. Also the system is very . -complex and complicated and is not suitable for working at , -a high speed. Besides, as the needles are solidly fixed, it is very -hard to replace them. Patent US 2740996 - PULLEY - proposes a head with rotating needles, the needles being positioned on a plurality of bars rotating along a circumference. A set of rollers present at the ends of the bars and . -cooperating with external cams positions the needles before, .during and after the drawing action. The DUDLEY invention also has a very limited working zone and too few combs to be able to function satisfactorily. -1-loreover, the system employed to rotate the combs is expens .ive, as also are the individual combs, without doubt; besides, their replacement is very complicated. Patent FR 1248933 - PRINCE - SMITH - proposes a device with two huge paired wheels which have a plurality of radial slots. Within these slots can run the heads of needle bars,. .of which the radial displacement is conditioned by a cam and -countercan. . According to this invention the tract where the sliver. Cooperates with the needles is devoid of the countercam, so. .that centrifugal force improves total penetration. This in-. .vention has a very long and irregular control zone. The sliver has to follow a broken line consisting of two arcs and a straight line. The drawing action is presum- .ably divided into two zones. In view of the considerable inertia of the system, it . is not suitable for working at high rotation speeds. Patent DE OS I5I0455 - VEB - proposes a device which . .also comprises two opposed flanges with radial slots cooper- .ating vath needle bars shaped like an omega. According to the description we seem to be able to un- -derstand that this invention discards the intersecting con-. cept and proposes expressly a control with only the lover .needle field. . The presence of a cam and countercam positions the bars However, we are not told how the bars can be kept in align- mend. For cleaning purposes a split pnewnatic system is visu- realized, partly blowing and partly sucking, with the possible lity of intersection between the two parts. The sucking oper ation could lead to the build-up of lumps. In fact, in the zone where the sliver leaves and where. the combs have to abandon the fibres pulled by the drawing , rollers 7 a suction device is envisaged to aspirate the dirt, but this device increases the adherence of fibres to the combs and not their separation therefrom, thus accentuating, the formation of lumps The description also speaks of alternated bars and bars differing from each other (but not shovin); such a system does not improve the control but instead makes it more uncertain, The patent in itself cannot be realized and remains a -mere exercise in proposals. Patent IT 8I8249 - G EMONI - proposes some auxiliary blades for cleaning the needles; the blades cooperate with .disks having multiple through millings (radial) and with la teral flanges having their circuit machined to provide a cam, said circuit cooperating with the ends of the needle bars and with the auxiliary cleaning blades. This patent enjoins the installation of double needle bars, which are consequently heavy and unsuited to high . speeds. The speed is also restricted by the radial disposit -ion of the millings. Patent ES 242206 - ESTIVILL - proposes a rotating head. -with combs, wherein the combs are circumferentially position .ed by two opposed flanges, whilst they are radially disposed .by two external cams. - This patent has the shortcoming of comprising weak .grooved flanges, since the tapering towards the middle of .the grooves involves a weakening that prevents the flanges from resisting fatigue. Moreover, the proposed system of -cans is imperfect and unsuitable for use. Furthermore, severe difficulties in cleaning the inside .will be met inasmuch as access thereto is impossible unless the machine is stopped and a plurality of combs is removed.. Patent ES 29I5I7 - ESTIVILL - proposes some improvements -to the foregoing ES 242206. Said improvements concern an improved cam system which encloses the whole course, the could ing of two rotating heads to widen the drawing field, the provision of outside cleaning means, and other aspects of little importance. Besides being part of the already known art, all these improvements do not modify the shortcomings of the original. patent. During the course of the description of this patent the intersecting lay-out is also proposed, namely the lay-out- with two mutually cooperating heads superimposed one above . .the other. Patent ES 386439 - ESTIVIL proposes, in fact, a solut-. ion with an intersecting design, as given earlier in ES 291517. This patent does not overcome the problems involved in. patent ES 242206 but makes them worse on both the rotating , heads. Our invention therefor, contains a plurality of im- . -provements to the knovn art from which it springs and which, it innovates profoundly, overcoming many problems which hither to have not been solved and which have always constituted, . up to the present time, a limitation for this type of comb . field. The invention therefore, tends to bring about many ad vintages, among which we can cite the following: the reduction of the distance travelled by the outgoing - sliver, so that shorter fibres too can be processed; - the higher working speed and, therefore, the higher output of the machine without any fall in product quality, since. . the mechanical organs can be dimensioned so as to be stronger because the limitations imposed by the known solutionsare. lacking; - a lessening of vibrations, a greater continuity of feed, a better transmission of motion and an increase in mechanic . al efficiency, the whole being obtained with a new and sim- . plified kinematic drive motion; -perfect alignment, phase setting and maintenance of align- ment of the combs whether during processing or when the organs are open, owing to an improved system for controll- . ing the opposed positions; - an increased life of the combs in that it is possible to dimension them to meet the stresses which they will under go, since the design limitations imposed before are now lacking; ; elimination of problems linked to the cleaning of the cham . bers formed by the inside space enclosed by the combs, for - it is possible to keep the chambers thenselves under pressure very simply. These and other advantages which will become clear from .the description hereinafter are pursued by the invention. The invention, therefore, consists of improved gill boxes with rotating heads, which comprise a plurality of needles .(teeth) acting on an assemblage of slivers fed substantially continuously, and are composed of a feed group, a fibre-con- trol group consisting of a pair of heads with combs super- imposed one above the other and rotating in opposite directions, and a drawing group, said gill boxes being character- ized by the fact that they comprise at least part of the .following improvements in reciprocal cooperation and coordi- nation: rotating means to guide the combs radially at their ends, .- stationary guide-can means cooperating in an intermediate. - position between the needle field and said rotating guide. . means, means to lubricate the radial rotating guides, - means to feed and convey fluid under pressure into the zone of the outgoing slivers and within every needle field, - means to ensure a path of differentiated insertion of the needles into the sliver, means for perpendicular departure of the needles from the sliver, means for individual protrusion of the needles so that they can be kept cleaner, - means for pulling said rotating guide means in phase with the motor, - means to reduce angular play, ¯ means to reduce the distance travelled by the outgoing .silver. The innovations will be described now with the help of the attached drawings, which are provided as non-restrictive .examples and in which is shown a preferential gill box with rotating heads. In the tables we have the following: wig. I shows a crosswide vertical section of an improved , gill box with rotating heads; Fig. 2 shows a lengthwise vertical section of the gill box .of Fig.I; -Fig. 3 shows the guide cams and shafts of the gill box of Fig.1; -Fig. 4 shows a variant of Fig. 3; -Fig. 5 shows the installation of the combs in the device . .according to the invention, .Fig. 6 shows a comb according to the invention; Fig. 7 shows a crosswise section of a comb according to Fig. 6. Reference to the figures gives the following; the mo- ion is transmitted by a motor organ of any desired type IO. -to the wheel II, which sets the gear wheel I2 in rotation. The gear wheel 12 and the wheel II are mounted, posit-. ioned and supported on the stationary frame I3, which is in. .coordinated cooperation with the frame I4, which can be moved in its upper part or be folded book-wise to facilitate access to the needle field and thus to facilitate the operations of .feeding the sliver and cleaning. The gear wheel 12 meshes with a gear wheel I5 solidly fixed to the disk with the grooves or guides 16; the disk I7 bas a circumferential toothing which serves to transmit mo tion to the coordinating bar 18 through the gear wheels19 ¯ .119 and to transmit motion to the flange 117 bearing the slots 116. Both the flange I7 and the flange 117 are positioned in opposed pairs, so that the slots I6 or 116 face each other The pairs of flanges 17-117 are connected by the bar 18 through gear wheels 19-119- This causes the flanges 17 and . also the flanges 117 to rotate constantly in a coordinated manner. - The lay-out realized also enables the motion coming from 12 to be equally distributed not only along one path but through to different paths, namely through the shafts I8 118 and through direct transmission between the flanges 17 , and flanges I17. - This direct transmission lessens the angular play between the upper and lower heads; the lower head or lower needle field is indicated as a whole with the number 21, while the upper head or upper needle field is indicated with 20, The upper head 20 can be fully opened by being made to rotate around the axis 120, the two needle fields being . rendered accessible in this way. - The play is lessened because the kinematic mechanism -is simplified to consist of a simple pair of gear wheels, -whereas in all known models a set of at least four gear .wheels has had to be employed. The lessening of the play and vibration leads substant .ially to a consiaerable technological improvement in the sli .ver producted. In the slots 16 and 116 can run the combs 22, which com .prise at their ends a substantially plane-parallel zone 23, while the needle field 24 lies in a middle position. Between the needle field and the plane-parallel end zone 23 there is the zone 25, which comprises at its corners .some rounded-off areas 26 suitable for improving the working .of the bar within the path imposed on it by the cams 27 and .28. According to the device the conbs have the needles in--- serted at a desired angle &alpha; to the lengthwise plane of the .comb The needles 29 are inserted advantageously at an in- - inclination and are installed in the gill box in such a way . .that their teeth are sloped in the opposite direction to that .of the forward movement of the combs. As shown in Fig.5, this conformation enables the slots 16 to be made very small since the combs are not streased too greatly in the transmis- simon zone. . This conformation of the slots 16 and, more generally. the conformation of the flange 17 enable a very strong guide .to be obtained between one slot 16 and its neighbour since . .the connection of the guide 30 to the flange I7 takes place. .at the rear and no longer in a zone near the niddle as in the previous models. According to the invention the slots I6 are not radial but are realized advantageously at a tangent to a concentric .circle, their inclination being in phase concordance or phase difference; it has been verified advantageously (see Fig.2). that it is more convenient for the overall phenomena to realize phase difference as regards the direction of rotation Hereinafter radial guides 16 are indicated in a generic and strong meaning, the foregoing being actually meant. As indicated, the upper head 20 and lower head 21 both. consist of to facing frames which uphold and support a shaft or stiffening and connecting bar 32, which by means of keys 39 becomes solidly fixed torsionally to the frames themselves. This stiffening bar 32 also serves to position and fix the internal cams 27, again with the employment of key means -39 or other means which are similar and produce the same -technical effect. Between the stationary frame 13 and the internal cam 27 is lodged the flange 17. The rotating flange 17 is sup -ported in a revolving manner by means of bearings on the stiffening and connecting bar 32. As said earlier, the stiffening and connecting bar 32 comprises a plurality of holes 34 which serve to feed the fluid under pressure, which flows out within the path of .the combs 22. Said pluralities of holes 34 work in coordinated coopt -eration with the diffusers 35 so that the chamber I24 circum- schibed by the combs 22 in the lower head 21 and upper head. -20 can be put under slight air pressure so as to facilitate. the departure of the fibres from the needles 29 in the drape ine phase. This overpressure also hinders the entry of dirt. -into the chamber circumscribed by the plurality of combs 22, As can be seen in Pig.2, the diffusers 35-135 cooperate -with the zones 44 and 45 where the combs leave the fibres -during the drawing phase. The conduit 36 feeds the lubricating fluid under pres- sure through 38 into the zone where the grooves or slots I6. or slots 16 rotate, so that said grooves 16, owing also to . .the centrifugal effect due to rotation of the flange I7, are lubricated constantly by said fluid under pressure. One or more alignment elements 51 are envisaged for sup -porting and positioning the internal conduit 36. At least one of said alignment elements 51 comprises some through channels .52 to permit the fluid under pressure 33 to pass to the holes 34. Owing to the conformation of the combs 22 it is possible to increase the production speed, since the carrying bar which constitutes the comb is very strong, the fatigue stress on . =the tongues 23 of the combs 22 being eliminated. As compared to the known combs, this elimination is brought about by having moved the tongues or plane-parallel. areas or block 23 to an end position. Owing to the new conformation of the combs made possible by the invention, the life of the combs 22 is greatly pro . -longed. This is the case because, in the zone where they co- operate with the cams 27 and 28, the combs are (or can be) . considerably wider and higher and therefore have a bigger -supporting surface. This bigger supporting surface in the zone 25 of the -combs 22 also leads to less wear on the cams 27 and 28. . - In particular, the greater width leads to less wear on. the cam 28, while the greater height leads to less wear on . the slots 116. If we look at Fig. 3, we can see that the external cam 28 is not continuous but is divided into two parts, 28 and . 42. In both cases the smaller part is located advantageously .on the upper side and can be readily detached to enable the. combs to be replaced quickly and easily. The closure insert. can be fixed directly on the cam 28, as shown in Fig. 3, or. the insert 42 can be fixed directly onto the frame 13 or 14. -with appropriate screws, as shown in Fig. 4; in this case -the insert 42 will have suitable clearances at its sides. This constructional detail enables a channel between the external cam 28 and the insert 42 to be eliminated, and. -this permits said external cam 28 to be deformed freely in . -an elastic manner under the mechanical impulses conveyed to. it by the combs 22. According to the invention, said external cam 28 can be constructed in such a way that its natural frequency is different from the frequency of the blows of the combs 22 -caused by the high speed of rotation; advantageously the na- tural frequency of vibration of the external cam 28 will be greater than the frequency of the blows of the combs 22 so .as to enable said external cam to be deformed under the iifr .pact of a comb 22 and to recover before the next comb strikes .it So as to improve the functioning still more in the zone -25, arrangements were made to make the corners round, as shown in Fig.7. The setting-up bar 18-118 is covered with a fixed pro-. .tective sleeve 53. This solution makes it possible to maintain communicat- ion between the two chambers located behind the cams 27 and. -28 on one side and the other and can be used advantageously. to naintain a circulation of cooling liquid, which also in-. vests the wheels I9 and the flanges 17. As is shown in Fig. 3, the cams 27 and 28 have a special conformation which is also a result of the studies and ex- -periments of the author. The zone 43, or zone of entry of the sliver, has been - designed so as to enable the needles of the upper field and. .the needles of the lower field to be inserted into the sliver without colliding against each other. . The shaping 46 of the upper cam I28 is advantageously . kept slightly curved so as to graduate the entry of the needle -les 29 into the sliver better, whereas the shaping 47 of the lower cam 28 is kept almost straight so as to obtain greater control of the sliver of fibres. The exits 44 and 45 have two different conformations. which reflect differentiated requirements in the behaviour of the needles 29 in respect of the sliver leaving the gill. -box. The exit 44 is located slightly more to the rear and has a more rounded shape than the exit 45. - The exit 45 with its more pointed and elongated shape - make possible a better control of the sliver even during its outgoing phase. Moreover, the conformation provided for the cams 27, 28, -I27 and I28, as can be seen in Fig. 3, is such as to permit. s substantially perpendicular departure of the needles 29 -from the sliver. In fact, the conformation given to the cams -27, 28, 127 and 128 enables a sharp variation to be obtained in the direction of speed of the combs 22 and thereby a perpendicular departure of the needles 29 from the sliver. The positions 48 and 49 ensure, instead, individual prot fusion of the combs from the grooves of the upper and lower. flanges so as to tnake possible the cleaning by means of the known system of rotating brushes. The sstem 68 of the rotating brushes can be envisaged. to comprise a rotating brush 62 and a needle-carrying 66 ^oscillating bar 65, which is contained viithin a tubular element having a plurality of holes 67 and which rotates around an offset centre 64. The feeder group shown in Fig.2 is envisaged as having three rollers 59, 6u and 61 but could also have only two rol less. The same can be said for the drawing system at the exit, which in our example is shown with three rollers 56, 57 and. -58. The distance travelled by the outgoing sliver is given -by the gap between the point 54 where the teeth 29 of the lower needle field leave the sliver and the point 55 where the rollers 56 and 57 grip the outgoing fibres. According to the invention said outgoing distance has been reduced to about 22-25 mm., and this permits any type of fibre to be processed with excellent results. e have described here a gill box improved with the ad- option of a plurality of characterizing innovations. However, it is possible to vary the proportions and sizes and to add, integrate and replace parts; it is possible to couple in series two or more gill box parts according to the invention or to use only one needle field, etc. Thee and other variants. remain within the scope of the idea of tile solution of the invention.

Claims: 1.Improved gill b@ h rotating heads, comprising a plur ality of needles that on an assemblage of slivers fed substantially continuosly, and composed of a feeder group (59-60-61), a group controlling the fibres which consists of a pair of heads with combs (20-21) superimposed one above the other and rotating in comparation, and a drawing group (54-55-59), said gill box being characterized by including at least part of the following improvements in mutual cooperation and coordination: : - opposed rotating means (17) to guide (16-30) the ends (23) of the combs (22), - fixed guide-cam means (27-28) cooperating in an intermediate position between the needle field (24) and said rotating guide means (17), - means (36-38) to lubricats said rotating guides (16-30), - means to feed (32-34) and convey (35) fluid under pressure into @ the outgoing zone (44-45) of he sliver and inside each needle flied (24), - means (46-47) to ensure a path of differentiated insertion of the needles (29) into the sliver, - means (44-45-16-30-22) for a perpendicular and non-interfering withdrawal of the needles (29) from the sliver, - means (48-49) for individual protrusion of the combs for better cleaning (62) of the needles (29), - pulling means (17-18-19) always in phase with said rotat- -ing guide means (17), means %(17-18-19) which reduce angular play - and means (54-55) which reduce the outgoing travelling distance of the sliver, 2. Improved gill box with rotating heads, as in Claim 1,characterized by the fact that the rotating means (17) comprise the grooves (16) separated by guides (30) solidly fixed ar heir rear to the flange body (I7), whereby said grooves (16) advantageously lie substantially at a tangent to a circle concentric with said flange (I7). 3. Improved gill box with rotating heads, as in Claim I or 2, characterized by the fact that the combs (22) have at their ends (23) sliding block means (23) cooperating with the guide means (30) present on the rotating means (17), and comprise, :between the needle field (24) and said combs (23), means (25) to cooperate with said stationary cam means (27-28). 4. Improved gill box with rotating heads, as in Claim I and in one or the other of the Claims thereafter, characterized ty the fact that the stationary guide-cam means (27-28) comprise means causing a path of differentiated insertion (46- 47), means to reduce the distance travelled by the outdoing. slivers (44-45) means (44-45) causing individual and perpen dicular withdrawal of the needles (29), and also means (42). for replacement of the combs (22). -5. Improved gill box with rotating heads, as in Claim I and. in one or another of the Claims thereafter, characterized by the fact that the outer part (28) of the stationary guide- . -can means is obtained advantageously with its frequency of vibration different from the frequency of the knocking of the combs (22), whereby said frequency of vibration of the - outer part (28) is greater than said frequency of the Icnocl-- ing of the combs (22). -6. Improved gill box with rotating heads, as in Clain I and -in one or another of the Claims thereafter, characterized by the fact that the perpendicular withdrawal of the needles (29) from the sliver is obtained with the coorcinated coop- eration of the means (44-45) present in the cam means (27-28) together with the inclination of the guides (30) in the rotating means (17), vith the conformation of the zone of travel (25) of the combs (22) omzd with the inclination of the needles (29), whereby the means (44) lie advantageously further to the rear th@ means (45). -7. Improved gill box @@v@ otating heads, as in Claim I and in one or another of the Claims thereafter, characterized by the fact that the reduction in angular play is obtained thr ough the coordinated cooperation of the rotating means (17). with the combs (22) and also of the cam means (28) with the zone of travel (25) of said combs (22), whereby the rotating means (17) of the two needle fields (20-21) are directly mes -hed together and are connected to the frontally positioned reciprocal rotating means (17) by shaft means (T8) bearing . gear wheels (19-119) meshed to said rotating means (I7)2 8. improved gill box with rotating heads, as in Claim I andin one or another of the Claims thereafter, characterized by -the fact that the internal chamber (I24) of the needle field is kept under pressure by fluid under pressure fed (33-34) and at least partially delivered by diffusers (35) in the zone (44-45) where the combs (22) leave the silver of fibres. 9. Improved gill box with rotating heads; as in Claim I and. one or another of the Claims thereafter, characterized by the fact that the reduction in the distance travelled by the outgoing slivers is obtained with the substantially pointed. conformation (45) of the cams (27-28) of the lower needle field (21). 10. Improved gill box with rotating heads, as in Claim @ I a-nd n one or another of the Claims thereafter, characterized by -the fact that the upper head (20) can be opened by being rot- atend onto a rearward axis (120). II. Improved gill box with rotating heads, as in Claim T and in one or another of the Claims thereafter, as described and shown and for the purpose allowed.

Inventors: VIAGGI, FERDINANDO
Applicants: OFFICINE SAVIO S.P.A.
Application year: 1981
Main classification: D01H5
IPC codes: D01H5