CIRCULAR KNITTING MACHINE

Abstract: The invention relates to a circular knitting machine with a needle cylinder (1) arranged on a carrier (2) of the needle cylinder (1) with a coaxially arranged toothed rim (5) of the drive (2) for the needle cylinder (1) and with a bearing body (6) arranged on the bed (7) of the machine surrounding the carrier (2) of the needle cylinder (1). The bearing body (6) comprises four in pairs mutually opposite bearing races (8a, 8b, 9a, 9b) out of which two are situated on the carrier (2) of the needle cylinder (1) and the other two are situated on the bearing body (6). Situated between the bearing races (8a, 8b, 9a, 9b) are bearing balls, and a part of the bearing races (8a, 8b, 9a, 9b) is mounted radially and/or axially movable in relation to the machine bed (7) and/or in relation to the carrier (2) of the needle cylinder (1). The bearing body (6) is equipped with a pair of outer bearing races (9a, 9b) arranged in a bearing ring (16) and is situated over the toothed rim (5) of the drive for the carrier (2) of the needle cylinder (1). The bearing ring (16) is to a limited extent (16) movable in the radial direction. The invention also relates to a circular knitting machine in which the bearing body (6) carries a pair of inner bearing races (8a, 8b) arranged in the bearing ring (16) and is situated over the toothed rim (5) of the drive for the carrier (2) of the needle cylinder (1). The bearing ring (16) is to a limited extent (16) movable in the radial direction.

Description: Circular knitting machine Technical field The invention relates to a circular knitting machine with a needle cylinder arranged on a carrier of the needle cylinder with coaxially arranged toothed rim of the drive of the carrier of the needle cylinder and with a bearing body arranged on a machine bed surrounding the needle cylinder carrier in which the bearing body comprises four in pairs mutually opposite situated bearing races, two of which are situated on the needle cylinder carrier, and the other two, on the bearing body, with bearing balls situated between the bearing races, and with a part of the bearing races mounted radially and/or axially displaceably in relation to the machine bed and/or to the needle cylinder carrier. Background art In circular knitting machines, considerable part of the energy supplied by the drive is transformed into heat by the needle movement so that the needle beds and needle cams are the warmest areas of the machine and the needle cylinder carrier extends by heat in diameter by as much as tenths of a millimeter more than the cooler machine bed. To prevent excessive load on the bearing due to such dimensional variations, modern knitting machines make use of heat-compensated machine groups. Knitting machines of this kind are known for instance from the patent DE 2829678 where one of the bearing races is mounted, and adapted axially to move, on a radially arranged resilient flange. In an improved arrangement disclosed in the patent specification DE 3906773 A1 , two axially adjacent bearing races are resiliently seated, each of them on a separate radially or axially arranged flange so as to permit the bearing races to move axially or radially. In another embodiment, disclosed in US 5 493 876, an arrangement is described in which the needle cylinder carrier or the machine bed has a pair of axially adjacent bearing races seated in the bearing ring which latter is connected by shifting with the needle cylinder carrier or with the machine bed by means of a connector permitting radial displacement and leaning against a resilient, axially arranged strip made as an integral part of the needle cylinder carrier or of the machine bed or of the bearing ring and acting as a heat compensator. The bearing races and the heat compensator are arranged on the needle cylinder carrier in the direction from the needle cylinder carrier downwards and on the machine bed in the direction from the machine bed upwards. Known methods of heat compensation on knitting machines have some grave drawbacks. The arrangement with one spring-biased bearing race requires a relatively large size of the compensation flange and is sensitive to manufacturing tolerances. The arrangement with two spring-biased bearing races requires for obtaining long service life of the bearing a relatively soft spring-loading which can lead to a radial displacement of the needle cylinder carrier as a consequence of the radial forces coming from the machine drive and acting on the toothed rim of the needle cylinder carrier. Due to its position under the needle bed carrier, the arrangement with the connector and with a resilient heat compensator requires a machine bed shape undergoing twisting as a consequence of the heat and force unbalance due to heat dilatations when the machine is heated. Besides, the bearing of the carrier of the cylindrical bed arranged in this way is not easily accessible and in case of a repair requires the dismantling of a considerable part of the machine which places heavy demands both on the repair time and on repair costs. The invention intends to remove or at least to minimize the drawbacks of the background art. Principle of the invention The goal of the invention has been reached by a circular knitting machine with a heat-compensated bearing whose principle consists in that the bearing body is equipped with a pair of outer bearing races situated in a bearing ring and is situated over the toothed rim of the drive for the needle cylinder carrier and that the bearing ring is to a limited extent movable in the radial direction. This arrangement provides for the positioning of the bearing on an easily accessible place and for its easy exchangeability. The radially movable seating also permits the heat expansion of the outer bearing races with all the positive effects. The bearing is seated at the narrowest place of the machine bed and its seating is therefore very exact and stable. Another advantage of the invention consists in the possibility of arranging the bearing body so as to reduce heat transfer into the machine bed. If the heat extension of the inner bearing races surpasses in amount the heat extension of the outer bearing body, the preload of the bearing and due to this also the heat generated by rolling-contact forces in the bearing increases and thus heats the outer bearing body which increases its extension and thus reduces the preload of the bearing. In this way, the outer bearing body automatically keeps the preload of the bearing and compensates the heat extension of the needle cylinder carrier. The very character of the problem shows that an analogical, in principle a reverse arrangement to the described solution, is easily possible. In this solution, the bearing body has a pair of inner bearing races arranged in the bearing ring and is situated over the toothed rim of the needle cylinder carrier drive. The bearing ring is to a limited extent movable in a radial direction. Although in this variant, the self- regulation function of the variations in the preload of the bearing due to the difference in the heat extensibility of the machine parts in question will be diminished, this drawback can be compensated for instance by increasing the elasticity of the bearing ring. Description of the drawings The invention is schematically shown in the drawings in which Fig. 1 is a cross section through the machine bed with the needle cylinder carrier with the bearing, through the needle cam block carrier, needle cylinder and needle cam blocks, with the bearing body with radially arranged flange with guide grooves on its circumference, Fig. 2 is a view from above of a guide member consisting of a pin and a cube with a circular aperture, Fig. 3a is a detail of a horizontal section through a guide member of the Fig. 3a, and Fig. 4 is a cross section through the machine bed of the Fig. 1 with the bearing body consisting of a bearing ring, an attachment flange, and a resilient connection between these members. Specific description The invention will be described in more details on the example of embodiment shown in Fig. 1. The circular knitting machine comprises a needle cylinder Λ carrying knitting means and fixed on a carrier 2 of the needle cylinder !. Coaxially arranged on the carrier 2 is a toothed rim 5 of a drive of the carrier 2 of the needle cylinder 1 and a bearing body 6 arranged on a machine bed 7 surrounding the carrier 2 of the needle cylinder 1 with four mutually opposite positioned bearing races 8a, 8b, 9a, and 9b, out of which those designed with 8a and 8b are inner bearing races whereas the other two, designed with 9a and 9b, are outer bearing races. The inner bearing races 8a and 8b are situated on the carrier 2 of the needle cylinder Λ t and the outer bearing races 9a and 9b are situated on the bearing body 6. Between the bearing races 8a, 8b, 9a, and 9b, bearing balls 6a are inserted The outer bearing races 9a and 9b are seated radially movable in relation to the bed 7 in a bearing ring 16 on the bearing ring 6 situated over the toothed rim 5 of the drive of the carrier 2 of the needle cylinder 1.. The bearing body 6 carrying in the bearing ring 1j6 the outer bearing races 9a and 9b is by guide means connected with the bed 7 in a radially movable way. In a preferred embodiment shown in Fig. 2, the guide means consist of grooves 12 provided on the circumference of the flange 17 of the bearing body 6 and cooperating with guide members inserted in them such as exactly mating cubes 3 arranged on pins 14 pressed in parallel with the machine axis in the contact surface of the bed 7 of the machine for the machine flange 17. During the heat extension (expansion) of the bearing body 6, the flange 17 is free to move radially in relation to the bed 7 of the knitting machine. The guide grooves 12 and the cubes 13 are so arranged that they have in the radial direction the play required for the mutual motion of the bearing body 6 and of the needle cylinder 1 while their play in the tangential direction is a minimal one as required for exact guiding. Due to this, the bearing body 6 can radially expand while maintaining exact coaxial position with a carrier 3 of needle cam blocks of the needle cylinder Λ with the needle cam system 4. In the preferred embodiment shown in Fig. 1 , the axial position of the carrier 3 of needle cam blocks, in particular in single- bed knitting machines, is adjusted by a nut 1 for the central adjustment of the stitch length which is on its inner side fitted with a thread 11a, and on its outer side with a gearing 11b into which a not represented pinion serving to adjust the stitch length enters. The nut 11. preferably leans against the upper surface of the flange 17 of the bearing body 6 and so achieves a more exact parallelism of the axes of the carrier 3 of needle cam blocks and of the carrier 2 of the needle cylinder ±. Fig. 2 is a view from above on the guide means consisting of the groove 12 on the circumference of the flange 17 with the inserted cube 13 on the pin 14. The exact position of each cube 13 on the bed 7 can be obtained for instance by flushed boring and pinning after the adjustment of the position of the carrier 2 of the needle cylinder ! Another preferred embodiment of the guide means in which the flushing boring is not necessary is shown in Figs. 3a, 3b. In the example of embodiment shown in Fig. 3a, the pin 14 carries an eccentric 15 on which the cube 13 is set. Fig. 3b shows the cross section through the embodiment of Fig. 3a. By adjusting the angular position of the eccentric 15 by means of a hexagonal orifice in its upper part the tangential play can be adjusted to an extent sufficient to do away with the need for flushing boring of the cube 13 with the machine bed 7. The play is preferably adjusted by means of the eccentric 15 in the neighbouring grooves 12 alternately on the remote side of the grooves 12 in such a manner that the bearing body 6 is free radially to expand but locked against the shifting and tangential rotary displacements. The eccentrics 15 can conveniently adjust also the position of the bearing body 6 in relation to the bed 7 of the knitting machine. In a preferred embodiment shown in Fig. 1 , the flange 17 leans against the machine bed 7 only in the area of the recess 17a. This reduces the heat transfer from the bearing body 6 into the machine bed 7, and the temperature of the bearing body 6 comes near to the temperature of the carrier 2 of the needle cylinder JL Due to this, the radial extension of the inner bearing races 8a, 8b is practically the same as that of the bearing ring 16 with the outer bearing races 9a, 9b, and the bearing shows no increased load in heated machine. An analogical mutual approach exists in the heat extension of the nut V\_ and the bearing body 6 so that the nut 1J. then can be led more exactly by the guide recess 11c which improves the precision of the stitch length setting. Fig. 4 shows another preferred example of embodiment of the knitting machine with the heat-compensated bearing according to the invention. The function is identical with the embodiment shown in Fig. 1 but for the fact that the bearing body 6 consists of the bearing ring 16 connected by a resilient connecting member 18 with the flange 17 fixed by bolts 19 with the machine bed 7. The connecting member 18 is resilient in the radial direction and permits the heat extension of the bearing ring 16. Its reduced cross section and height considerably cut the heat transfer from the bearing ring 16 into the machine bed 7 so that the extension of the bearing ring 16 equals that of the inner bearing races 8a, 8b. The increased heat resistance of the connecting member 8 further increases the self-adjusting function of the bearing load. At increased preload, the bearing ring 16 increases its temperature and extends, thus reducing the preload. By calculation, the heat and operation conditions can be conveniently proposed so as to ensure a constant preload of the bearing regardless of the variations in the machine temperature. In Fig. 4, the carrier 3 of needle cam blocks is shown without the setting nut. This embodiment will be used as a rule in double-bed knitting machines. It is self-evident that the arrangement with the bearing body 6 shown in Fig. 4 admits the use of the carrier 2 of the needle bed 1 with the setting nut 11 As is shown in Figs. 1 and 4, a part of the carrier 2 of the needle bed 1 is made as radially resilient compensation member, preferably U-shaped. This compensation member has resilient arms 20 and a connecting annulus 21 The elasticity of the compensation member limits both radial and torsional heat deformations of the carrier 2 of the needle cylinder 1 In a not represented example of embodiment, the bearing can be so arranged that the bearing body, situated over the toothed rim of the drive for the needle cylinder carrier, has a pair of inner bearing races situated in a bearing ring and that the bearing ring is to a limited extent radially movable. The bearing body is mounted on the needle cylinder carrier by means of a member with reduced cross section so as to limit the heat transfer from the needle cylinder carrier into the bearing ring and into the machine bed. The bearing body also comprises a substantially radial flange fitted on its ' inner circumference with grooves into which guide members mounted on the needle cylinder carrier enter. The guide members are made equivalently to those of the shown embodiment. Like in the shown example of embodiment, the radial flange of the bearing body is equipped with a recess by means of which it is mounted on the needle cylinder carrier. The contact surface between the needle cylinder carrier and the recess of the radial flange of the bearing body is shaped as an annulus, and a gap exists between the remaining surface of the radial flange and the needle cylinder carrier. In another embodiment, the bearing ring fitted with a pair of inner bearing races is connected by means of a resilient connecting member with a flange fixed on the needle cylinder carrier, and the bearing ring is an integral part of the bearing body. The resilient connecting means is made as a thin-walled cylinder coaxial with the axis of the machine. The examples of embodiment given above do not limit the scope of the invention to the described and shown embodiments which can be used both separately and in combinations not expressly described and shown.

Claims: PATENT CLAIMS 1. Circular knitting machine with a needle cylinder arranged on a carrier of the needle cylinder with coaxially arranged toothed rim of the drive of the carrier of the needle cylinder and with a bearing body arranged on a machine bed surrounding the needle cylinder carrier in which the bearing body comprises four in pairs mutually opposite situated bearing races, two of which situated on the needle cylinder carrier, and the other two, on the bearing body, with bearing balls situated between the bearing races, and with a part of the bearing races mounted radially and/or axially displaceably in relation to the machine bed and/or to the needle cylinder carrier, characterized by that the bearing body (6) is equipped with a pair of outer bearing races (9a, 9b) situated in a bearing ring (16) and is situated over the toothed rim (5) of the drive for the carrier (2) of the needle cylinder (1) and that the bearing ring (16) is to a limited extent movable in the radial direction. 2. Circular knitting machine as claimed in Claim 1 , characterized by that the bearing body (6) is mounted on the bed (7) of the knitting machine by means of a member having a reduced cross section so as to limit the heat transfer from the bearing ring (16) into the bed (7) of the knitting machine. 3. Circular knitting machine as claimed in any of Claims 1 and 2, characterized by that the bearing body (6) comprises a substantially radial flange (17) fitted on its outer circumference with guide means for guiding the flange (17) in radial direction. 4. Circular knitting machine as claimed in Claim 3, characterized by that the guide means for guiding the flange (17) in radial direction consist of grooves (12) into which guide members mounted on the machine bed (7) are inserted. 5. Circular knitting machine as claimed in Claim 4, characterized by that the guide members are made as cubes (13) of substantially rectangular shape fitted with circular aperture and that each aperture provided in the cubes (13) carries an eccentric (15) whose axis is parallel with the axis of the machine and which is rotatably connected with the machine bed (7) for defining the tangential play of the cube (13) in the groove. 6. Circular knitting machine as claimed in Claim 4, characterized by that the guide members consist of cubes (13) of substantially rectangular shape fitted with circular aperture and that each aperture provided in the cubes (13) carries a pin (14) whose axis is parallel with the axis of the machine and which is connected with the machine bed (7). 7. Circular knitting machine as claimed in any of Claims 3 to 5, characterized by that the radial flange (17) of the bearing body (6) is fitted with a recess (17a) by means of which the radial flange (17) is seated on the machine bed (7), the contact surface of the machine bed (7) with the recess (17a) of the radial flange (17) being shaped as an annulus while there is a gap between the remaining surface of the radial flange (17) and the machine bed (7). 8. Circular knitting machine as claimed in Claim 1 , characterized by that the bearing body (6) comprises the flange (17) fixed to the machine bed (7) and that the bearing ring (16) is connected with the flange (17) by means of a resilient connecting member (18) made as an integral part of the bearing body (6). 9. Circular knitting machine as claimed in Claim 7, characterized by that the resilient connecting member (18) is made as a thin-walled cylinder coaxial with the axis of the knitting machine. 10. Circular knitting machine with a needle cylinder arranged on the needle cylinder carrier with coaxially arranged toothed rim of the drive for the needle cylinder carrier and with the bearing body arranged on the machine bed and surrounding the needle cylinder carrier in which the bearing body comprises four in pairs mutually opposite situated bearing races out of which two are situated on the needle cylinder carrier, and the other two are situated on the bearing body, with bearing balls situated between the bearing races and with a part of the bearing races seated radially and/or axially displaceable in relation to the machine bed and/or to the needle cylinder carrier, characterized by that the bearing body (6) has a pair of inner bearing races (8a, 8b) arranged in the bearing ring (16) and is situated over the toothed rim (5) of the drive for the carrier (2) of the needle cylinder (1) and the bearing ring (16) is to a limited extent movable in the radial direction. 11. Circular knitting machine as claimed in Claim 9, characterized by that the bearing body (6) is seated on the carrier (2) of the needle cylinder (1 ) by means of a member featuring a reduced cross section so as to limit heat transfer from the carrier (2) of the needle cylinder (1 ) into the bearing ring (16) and into the machine bed (7). 12. Circular knitting machine as claimed in any of Claims 9 and 10, characterized by that the bearing body (6) comprises a substantially radial flange (17) whose inner circumference carries grooves (12) cooperating with guide means seated on the carrier (2) of the needle cylinder (1 ) and inserted into the grooves (12). 13. Circular knitting machine as claimed in Claim 11 , characterized by that the guide members are made as substantially rectangular cubes (13) fitted with circular aperture and that each aperture in the cubes (13) contains an eccentric (15) whose axis is parallel to the machine axis and which is rotatably connected with the carrier (2) of the needle cylinder (1 ) for defining the tangential play of the cube (13) in the groove. 14. Circular knitting machine as claimed in any of Claims 11 and 12, characterized by that the radial flange (17) of the bearing body is fitted with a recess by means of which the radial flange (17) is mounted on the carrier (2) of the needle cylinder (1 ) and that the contact surface of the carrier (2) of the needle cylinder (1 ) with the recess (17a) of the radial flange (17) is shaped as an annulus while there is a gap between the remaining surface of the radial flange (17) and the carrier (2) of the needle cylinder (1 ). 15. Circular knitting machine as claimed in Claim 9, characterized by that the bearing body (6) comprises the flange (17) fixed to the carrier (2) of the needle cylinder (1) and that the bearing ring (16) is connected with the flange (17) by means of a resilient connecting member (18) which is an integral part of the bearing body (6). 16. Circular knitting machine as claimed in Claim 14, characterized by that the resilient connecting member (18) is made as a thin-walled cylinder coaxial with the machine axis. 17. Circular knitting machine as claimed in any of Claims 1 to 15, characterized by that the bearing races (8a, 8b, 9a, 9b) are ring-shaped. 18. Circular knitting machine as claimed in Claim 16, characterized by that the wires of the bearing races (8a, 8b, 9a, 9b) are circular in cross section. 19. Circular knitting machine as claimed in Claim 16, characterized by that the wires of the bearing races (8a, 8b, 9a, 9b) are rounded non-circular in cross section. 20. Circular knitting machine as claimed in Claim 16, characterized by that the wires of the bearing races (8a, 8b, 9a, 9b) are rectangular in cross section. 21. Circular knitting machine comprising a needle cylinder arranged coaxial on a needle cylinder carrier with coaxially arranged toothed rim of the drive for the needle cylinder carrier and with a bearing body arranged on a machine bed and surrounding the needle cylinder carrier in which the bearing body comprises four in pairs mutually opposite bearing races out of which two are inner bearing races and are arranged on the bed carrier, and the other two are outer bearing races and are arranged on the bearing body, with bearing balls situated between the bearing races and with the outer bearing races being mounted movable in relation to the machine bed, characterized by that a radially resilient compensation member is inserted between the inner parts of the carrier (2) of the needle cylinder (1 ) and the outer parts of the carrier of the needle cylinder. 22. Circular knitting machine as claimed in Claim 20, characterized by that the compensation member has at least two sections coaxial with the axis of the knitting machine and at least one section perpendicular to the axis of the knitting machine. 23. Circular knitting machine as claimed in Claim 21 , characterized by that the compensation member is U-shaped and is situated downwards from the disc section of the carrier (2) of the needle cylinder (1 ).

Inventors: PISKULA FRANTISEK, PISKULA, FRANTISEK
Applicants: AMTEK SPOL S R O, PISKULA FRANTISEK, AMTEK, SPOL. S R.O., PISKULA, FRANTISEK
Application year: 2001
Main classification: D04B15
IPC codes: D04B9, D04B15