SPINNING ROTOR OF AN OPEN-END SPINNING MACHINE

Abstract: The invention refers to a spinning rotor of an open-end spinning machine for spinning the yarn with high proportion of up to 100% flax fibres. The spinning rotor comprises an inlet aperture (1) leading into a gradually widening gliding surface (2) which passes into an auxiliary gliding surface (21), which then passes into a collecting groove (3). The collecting groove (3), which comprises an overflow surface (31), a transfer surface (32) and a defining surface (33) passes steplessly into the inner surface (4) of the bottom (5) of the spinning rotor. The bottom (5) of the spinning rotor comprises ventilation channels (6), which pass through from the inner surface (4) of the bottom (5) of the spinning rotor to the outer surface (7) of the bottom (5) of the spinning rotor. The bottom (5) of the spinning rotor also includes the ventilation grooves (8) that connect the spinning rotor cavity with the ventilation channels (6). To each ventilation channel (6) leads one ventilation groove (8), the front surface of which (81) is inclined to the plane perpendicular to the axis of rotor rotation and passes into the inner surface (4) of the bottom (5) of the spinning rotor near into the defining surface (33) of the collecting surface (3). Each ventilation groove (8) is displaced with respect to the axis of symmetry of its related ventilation channel (6) in the direction opposite to the rotor rotation.

Description: Spinning rotor of an open-end spinning machine Field of the invention The invention relates to a spinning rotor of an open-end spinning machine, a cavity of which comprises a gliding surface followed by a collecting groove passing into an inner surface of rotor bottom which includes ventilation channels and through- going ventilation grooves. Background of the Invention Open-end spinning of flax fibres is generally a very difficult problem, as the flax fibres are substantially hard and their surface is considerably broken, especially due to the impurities coming into being in the course of the fibre production. While being spun, even into mixed yarn, the flax fibres get caught by the impurities on the edges of the spinning rotor cavity, which causes frequent fouling of the ventilation channels and also frequent breakages, which makes it impossible to achieve the needed spinning up and yarn quality. None of the currently used rotors is capable of spinning yarn, especially yarn spun from mixed yarn with high proportion of flax fibres, or pure flax fibre yarn because the air flow in such rotors does not have the needed qualities in combination with the needed level of self-cleaning abilities of these rotors. Mixed yarn with certain lower proportion of flax fibres, max. about 30% can be spun e.g. by a rotor according to CS AO 272017, which has a special shape of the collecting groove and the bottom of which comprises the ventilation channels. The disadvantage of this rotor is that only mixed yarn with comparatively low proportion of flax fibres can be spun on it due to the fact that if the share of flax fibres exceeds the maximum limit of about 30% the process of fibre band twisting into yarn is troubled by interruptions. Another rotor for open-end spinning of mixed yarn with certain proportion of flax fibres is disclosed in CS AO 254785, which describes a spinning rotor with a collecting groove, ventilation channels and ventilation grooves leading from the rotor cavity into the channels. This spinning rotor can be used only in spinning mixed yarn with very small proportion of flax fibres. Spinning of mixed yarn with higher proportion of flax fibres, or the pure flax fibre yarn is impossible, especially due to the inconvenient shape of the collecting groove because of which fibre band twisting into the yarn is not achieved. The aim of the invention is to invent a spinning rotor for an open-end spinning of the yam with up to 100% high proportion of flax fibres. Summary of the Invention The aim of the invention is achieved by a spinning rotor of an open-end spinning machine whose principle consists in that the collecting groove comprises a inclined overflow with curved transfer surface linked to the rotor bottom inner surface, which comprises a curved truncated lateral area of a cone, and the bottom of the rotor includes ventilation grooves each of which leads into its respective ventilation channel by which a change of the conditions in the spinning rotor cavity is reached and also the interception of flax fibres on the ventilation channels inlets is eliminated, which permits open-end spinning of yarn with up to 100% high proportion of flax fibres. Another advantageous embodiment consists in that the overflow surface comprises a lateral area of a truncated cone with taper angle of 10 - 20°, where the axis of symmetry is the same as the axis of rotation and this truncated cone is in the direction from the bigger base to the smaller base oriented to the inlet aperture, the transfer surface advantageously comprises circumferential surface of a toroid and the defining surface comprises lateral area of a truncated cone with taper angle of 50 - 59°, the axis of symmetry is the same as the axis of rotation and this truncated cone is oriented from the bigger base to the smaller base in the opposite direction as compared with the truncated cone, by which the lateral area forms the overflow surface, by means of which optimal conditions for fibre band twisting of pure flax fibres into yarn are obtained. Another advantageous embodiment, there is an auxiliary gliding surface provided between the gliding surface and overflow surface of the collecting groove, by which better conditions are reached in fibre transition from gliding surface onto overflow surface of the collecting groove. Another advantageous embodiment consists in that the auxiliary gliding surface comprises a truncated cone lateral area whose axis of symmetry is identical with the axis of rotor rotation and taper angle of this truncated cone is of 50 - 60°, and the truncated cone is in the direction from the bigger base to the smaller base oriented to the inlet aperture, by which the optimal conditions are reached for fibre transition from the gliding surface onto the overflow surface of the collecting groove. Another advantageous embodiment consists in that each ventilation groove is displaced with respect to the axis of symmetry of its corresponding ventilation channel in the direction opposite to that of the rotor rotation by which the positive influence of air flow on the process of flax fibre spinning and self-cleaning ability of the rotor is still more increased. Another advantageous embodiment consists in that of each ventilation groove is situated in a plane defined by the axis of rotor rotation and by the longitudinal axis of symmetry of its corresponding ventilation channel, and the opposite side surface of each ventilation groove is situated in a plane parallel to it, which is spaced from it less than half the diameter of the ventilation channels in the direction opposite to that of the rotor rotation thus eliminating one ventilation groove edge on its transition into the ventilation channel, by means of this achieving the optimal effect of air flow on the flax fibre spinning process with high self-cleaning ability of the rotor. The ventilation grooves advantageously comprise inclined front surface passing into the inner surface of the rotor bottom near the transition of the defining surface of the collecting groove into the inner surface of the rotor bottom, whereby maximisation of positive effect on the fibre band twisting into yarn is achieved. Brief Description of the Drawings Examples of embodiment of the invention are schematically shown in the drawings in which Fig. 1 is a sectional view of the spinning rotor according to the invention, Fig. 2 is a sectional view detail showing the collecting groove with ventilation channel and ventilation groove, Fig. 3 is a view into the spinning rotor cavity, Fig. 4 is a detail of the ventilation channel with ventilation groove, Fig. 5 is an embodiment of the spinning rotor with auxiliary gliding surface Specific Description The spinning rotor comprises an inlet aperture 1 leading onto a gradually widening gliding surface 2 formed by the lateral area of a truncated cone with a taper angle of 75°, the longitudinal axis of which lies in the axis of the rotor rotation and whose gliding surface 2 passes to a collecting groove 3. The collecting groove 3 passes steplessly into an inner surface 4 of the bottom 5 of the spinning rotor. The bottom 5 of the spinning rotor comprises ventilation channels 6, which pass through from the inner surface 4 of the bottom 5 of the spinning rotor to the outer surface 7 of the bottom 5 of the spinning rotor. The bottom 5 of the spinning rotor also includes ventilation grooves 8 that connect the spinning rotor cavity with the ventilation channels 6_in such a way that one ventilation groove 8 passes into each ventilation channel 6. The collecting groove 3 of the spinning rotor comprises the gliding surface 2 which is related to an overflow surface 3J_ which leads onto a transfer surface 32 which then passes onto a defining surface 33 which leads directly onto the inner surface 4 of the bottom 5 of the spinning rotor. Another example of spinning rotor embodiment shown in Fig. 5 there is an auxiliary gliding surface 21 situated between the gliding surface 2 and the overflow surface 31 of the collecting groove 3, the auxiliary surface 2J . being formed by the lateral area of a truncated cone the axis of symmetry of which is identical with the axis of rotation and the taper angle of this truncated cone is 50° - 60°, and the truncated cone is oriented in the direction from the bigger base to the smaller base to the inlet aperture The overflow surface 31. is formed by the lateral area of a truncated cone with taper angle of 10° - 20° where the axis of this cone is identical with the rotor axis of rotation and the truncated cone is oriented in the direction from the bigger base to the smaller base to the inlet aperture 1 of the rotor. In the lower part of the overflow surface 31.. the overflow surface 31 . is connected to the transfer surface 32, which is shaped as a part of a toroid surface with small diameter, by which the overflow surface 3J. passes over to the defining surface 33 which has the shape of the lateral area of a truncated cone with a taper angle of 50° - 59° and the truncated cone is oriented in the direction from the bigger base to the smaller base to the bottom 5 of the rotor any by its edge between its base and lateral area it passes into the inner surface 4 of the bottom 5 of the rotor , which has the shape of an inwards deflected lateral area of a truncated cone as shown in Fig. 1 and 2. The inner surface 4 of the bottom 5 passes into a closing surface 41 into which an aperture 42 for the well-known positioning of the rotor onto a not shown well-known shaft of the rotor leads. The ventilation channels 6 lead into the lower part of the inner surface 4 of the bottom 5 of the rotor over the closing surface 4 . and they are all over their length connected with the rotor cavity by the passing through ventilation grooves 8, where the ventilation grooves 8 are with respect to the axis of rotation of their related ventilation channels 6, displaced in the direction opposite to the rotor rotation as shown in Fig. 3. Another, not shown, example of spinning rotor embodiment consists in that the ventilation channels 6 are connected with the cavity of the spinning rotor by only a part of their length. The width of each ventilation groove 8 is lower than half the diameter of the ventilation channels 6, and the side walls of each ventilation groove 8 are parallel to each other. The ventilation grooves 8 are positioned in such a way that one of their side walls lies in the plane defined by the axis of rotation and the longitudinal axis of symmetry of the respective ventilation channel 6 as shown in Fig. 3 and Fig. 4, where the second side wall of each ventilation groove 8 is to the first side wall of this ventilation groove 8 displaced in the direction opposite to the rotor rotation. The front surface 8 of the ventilation groove 8 is inclined with respect to the plane vertically to the axis of rotor rotation and it passes into the inner surface 4 of the bottom 5 of the rotor near this inner surface 4 of the bottom 5 of the rotor transition into the defining surface 33 of the collecting groove 3 of the rotor, which is an embodiment shown in the drawings formed by a curvated surface. In another, not shown, example embodiment the front surface 8J . of the ventilation groove 8 is formed by a different type of surface.

Claims: Patent Claims 1.A spinning rotor of an open-end spinning machine, a cavity of which comprises a gliding surface followed by a collecting groove passing into an inner surface of rotor bottom which includes ventilation channels and through-going ventilation grooves, characterised by that the collecting groove (3) comprises an inclined overflow surface (31 ) which passes via an arched transfer surface (32) into an inclined defining surface (33) leading onto an inner surface (4) of the bottom (5) of the rotor, which is formed by an inwards deflected truncated cone while each ventilation groove (8) passing through its related ventilation channel (6)at least, into a part of its length. 2. A spinning rotor as claimed in Claim 1 , characterised by that the overflow surface (31 ) is formed by lateral area of a truncated cone, the axis of symmetry of which is identical with the axis of the rotor rotation and the taper angle of this cone is of 10° - 20° and the cone is in the direction from the bigger base to the smaller base oriented towards the inlet aperture (1 ) while the transfer surface (32) is formed by a part of a toroid and the defining surface (33) is formed by the lateral area of a truncated cone, the axis of symmetry of which is identical with the axis of rotor rotation and the taper angle of this cone is of 50° - 59° where the truncated cone is oriented in the direction opposite to that of the truncated cone whose lateral area forms the overflow surface (31 ). 3. A spinning rotor as claimed in Claim 1 and 2, characterised by that between the gliding surface (2) and the overflow surface (31 ) of the collecting groove (3) there is situated an auxiliary gliding surface (21 ). 4. A spinning rotor as claimed in Claim 1 to 3, characterised by that the auxiliary gliding surface (21 ) is formed by the lateral area of a truncated cone, the axis of symmetry of which is identical with the axis of the rotor rotation and the taper angle of this cone is of 50° - 60°, said truncated cone being oriented to the inlet aperture in the direction from its bigger base to its smaller base. 5. A spinning rotor as claimed in Claim 1 to 4, characterised by that each ventilation groove (8) is shifted in the direction opposite the rotor rotation with respect to the axis of symmetry of its related ventilation channel (6). 6. A spinning rotor as claimed in claim 1 to 5, characterised by that one side surface of each ventilation groove (8) is situated in the plane defined by the axis of rotor rotation and the longitudinal axis of symmetry of the respective ventilation channel (6) and that the opposite side surface of each ventilation groove (8) lies in a parallel plane spaced apart from it by less than a half of the ventilation channel (6) diameter in the direction opposite to the rotor rotation. 7. A spinning rotor as claimed in Claim 1 to 6, characterised by that the ventilation grooves (8) comprise a front surface( 81 ) which is inclined with respect to the plane perpendicular to the axis of rotor rotation and its transition into the inner surface (4) of the bottom (5) of the rotor is situated near the transition between the defining surface (33) of the collecting groove (3) into the inner surface (4) of the bottom (5) of the rotor. 8. A spinning rotor as claimed in Claim 1 to 7, characterised by that the front surface (81 ) of the ventilation groove (8) is formed by a curved surface.

Inventors: MLADEK MILOS, TESAR OLDRICH, MLADEK, MILOS, TESAR, OLDRICH
Applicants: MLADEK MILOS, RIETER ELITEX AS, TESAR OLDRICH, MLADEK, MILOS, RIETER ELITEX A.S., TESAR, OLDRICH
Application year: 1998
Main classification: D01H4
IPC codes: D01H4