US 3518845 A
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1970 A. DE CERJAT 3,518,845
SELECTING DEVICE FOR INDIVIDUAL SELECTION OF THE KNITTING TOOLS IN VERY FINE GAUGE KNITTING MACHINES Filed Nov. 14, 1967 2 Sheets-Sheet 1 3;; Q 4 22 Eg 5 Q a r 3 7 11 FIG. 2a FIG. 2b
Q 72 1 N I 2032 L. 1 1.0 E 1, 47 30 31 23\ S. 22 4a 39 1a\ $49 29 FIG. 3 14 FIG. 1
INVENTOR. AyMoN DE CERUAT July 7, 1970 A. DE CERJAT 3,518,845
SELECTING DEVICE FOR INDIVIDUAL SELECTION OF THE KNITTING TOOLS IN VERY FINE GAUGE KNITTING MACHINES Filed NOV. 14, 1967 2 Sheets-Sheet 3 ,1 n h I I FIG. 5
INVENTOR. A YM ON DE CE/QJAT United States Patent 6 Int. (:1. D04]: /78, 15/70 US. Cl. 66--50 10 Claims ABSTRACT OF THE DISCLOSURE The selecting device for individual selection of the knitting tools of a fine gauge knitting machine comprises a control electromagnet which is polarized by electric pulses according to a given programme for causing selective deviation of the knitting tools against one or the other of the pole faces of a magnet against which they are maintanied by magnetic adherence. The pushers of the needles are guided by partitions of non-magnetic material for the purpose of concentrating the magnetic flux to the pushers to be selected and preventing leakage across the partitions. The core of the control electromagnet has its end portion adjacent the needles relieved on the side of egress of the travelling tools, so that the pushers which have left the selecting position will no longer be influenced by the magnetic control field. The upper end of the coil of the control electromagnet is disposed on the highest possible level in close proximity to the pole face of the magnet core, and auxiliary magnets are provided for increasing the force of magnetic adherence and provide a safe locking of the selected tools.
The invention relates to selection devices for individual selection of knitting tools in very fine gauge knitting machines, of the kind comprising a magnet and a control electromagnet which is polarized by electric pulses according to a given programme, the electromagnet causing selective deviation of the knitting needles towards one or the other pole face of the magnet against which they are maintained by magnetic adherence.
An individual selecting device of the knitting tools, for example needles with pushers, effects sorting of the said tools into operative tools and inoperative tools, in view of obtaining designs, reliefs or fashioned articles.
Different types of electromagnetic selecting devices are known which use the principle of electromagnetic adherence of the pushers to the pole surface of an electromagnet which can be controlled by electric pulses according to a given programme. Among these known devices a particularly advantageous arrangement is de scribed in Swiss Pat. 396,284, US. Pat. No. 3,283,541. In this device the pushers are actuated exclusively by the forces of magnetic attraction and adherence for rendering them operative as well as inoperative. This same device combines the locking action with that of proper selecting, without leaving any discontinuity. The said device selects knitting tools in a safe manner as long as these latter are not too close to each other, that is to say that the gauge of the knitting machine is not very fine.
The considerable increase in price of the thread requires machines of very fine gauge, in order to avoid that this increase is found again entirely in the price of the knit articles.
The object of the present invention is to provide a selecting device for knitting machines of very fine gauge, by combining means for concentration of the magnetic control field in a very reduced area, by adding auxiliary magnetic barrier fields downstream of the selector section and by reducing to a maximum the paths of the magnetic fluxes other than those across the tools to be selected.
The device according to the invention comprises a control electromagnet having a core which is relieved on the side of egress of the knitting tools, a coil of said control electromagnet being disposed on the highest possible level about said core, the pole pieces of said magnet being relieved on the entrance side of the said tools, supplementary magnets on the side of egress of the said tools, and guiding partitions of non-magnetic material for said tools.
The accompanying drawings represent diagrammatically and by way of example different embodiments of a selecting device according to the invention.
FIG. 1 is a vertical section of an embodiment of the device as well as of a portion of the cylinder of a circular knitting machine.
FIG. 2a is a front view of a portion of the device.
FIG. 2b is a side view of this same portion.
FIG. 3 is a section along the line III-III of FIG. 1.
FIG. 4 is a vertical section of another embodiment of the device.
FIG. 5 is a section along the line VV of FIG. 4.
FIG. 6 is a transverse section of a portion of the device along the line VIVI of FIG. 5.
FIG. 7 is a plan view of a modification of a portion of the device.
FIG. 8 is a section along the line VIII-VIII of FIG. 7.
FIG. 1 shows a portion of the cylinder 1 of a circular knitting machine with a needle 2. The cylinder is provided in known manner with grooves 3 in which the needles are guided. Tht walls of the grooves in the lower portion of the cylinder are formed by added partitions 4. The needles 2 carry a male hinge member 6. The pushers are connected to the needles by the intermediary of a female hinge member 8 which envelops the said male hinge member, so that the pushers can effect an angular movement about this hinge member 6. Each pusher 7 carries a pusher butt 9 which, in contact with a cam 10 of the cam plate 11, imparts a determined axial movement to the pusher, and by the intermediary of the hinge 6, 8 to the needle 2. The pusher 7 is shown in its middle position, which position it occupies in the moment of the selection. The selecting device according to the invention places the pushers selectively in two well determined positions, namely in an inoperative and an operative position. In their inoperative position the pushers are sunk with their butt 9 in the grooves, and in their operative position the butts penetrate sufilciently deep into the cam plate 11 in order to be entrained by the earns 10.
The selecting device 12, in the different embodiments hereinafter described, uses the selecting method described in the Swiss Pat. No. 396,284. The device according to the present invention differs from the known device in that the magnetic control field is highly concentrated, that the permanent magnetic field is modified in its distribution as well as in its force, that the magnetic leakages are reduced, and that auxiliary fields are added to allow a safe selection when the knitting tools are very close to each other.
A first element of the invention which is common to the different embodiments described concerns the partitions 4 which guide the pushers 7 by their extensions 13 until into the interior of the selector stations. They are of non-magnetic material, for example of bronze having good anti-friction properties. In this manner, the mag netic fluxes are concentrated on the tools to be selected and the leakages across the partitions are substantially eliminated.
The selecting station comprises a magnet, an electromagnet and a support 14 of non-magnetic material which is fixed to the frame of the knitting machine. The magnet comprises pole pieces 18 and 19 the pole faces 20 and 21 of which make contact with the pushers 7, a core 17 and two identical coils 15 and 16 destined to be connected to a direct current source. The control electromagnet comprises a core 22 fixed to the center of the core 17, and a coil 23 destined to be connected to a source of polarized electric pulses according to a given programme. The selecting station so far described is known and its operation is explained in the Swiss Pat. No. 396,- 284.
A second element of the invention which is common to the different embodiments, is formed by the core 22 of the control electromagnet. This core and its end 24 adjacent the pushers, which is relieved on the side of egress of these latter, is shown in FIGS. 2a and 2b. The width of its pole face 27 measured in the direction of the arrow a, does not exceed one division. This pole face is limited, on the side of egress of the pushers, by a vertical face 26. Due to this shape of the end 24, the pushers 7', 7", 7" etc. having left the proper selecting section of the device practically are no longer influenced by the control field. The pole face 27 is limited on the side of entrance of the pushers by an inclined face 25. This face is provided as a mechanical alignment slope for pushers which may have descended too far and does not form a part of the invention. As already said before, the pushers are very close to one another in fine gauge machines and due to this fact it is possible that a pusher which just leaves the selecting section will be influenced by the control field destined to the following pusher and its proper selection will be disturbed. Thus it is necessary to increase the force of magnetic adherence in the amplifying zone by the addition of auxiliary magnets. FIGS. 1 and 3 show such adherence increasing means in the form of electromagnets 30 and 31 fixed to the pole pieces 18 and 19. When for example the pole piece 18 is N polarized, it is necessary that the auxiliary face 32 is S polarized to effect a safe locking. It is useful to protect the pole faces by a plate of wear resistant nonmagnetic material, for example of hard metal. Such a plate 36 disposed over the whole length of the channel, is shown in FIGS. 4, and 6. The pole faces and the friction face of the plate 36 must be aligned in the direction of movement of the pushers, and without steps nor discontinuities in the direction of travel of these latter. It is also possible to protect the pole faces by a deposition of wear resistant material, for example of hard chromium. FIG. 3 shows that the edges 28 and 29 limiting the pole faces 32 and 33 are set back for about one half division as seen in the direction of the arrow, with respect to the center of the face 27.
FIGS. 4, 5 and 6 show another embodiment of the auxiliary magnets in the form of permanent magnets 34, 35, fixed to the pole pieces 18, 19 and carrying themselves auxiliary pole pieces 37, 38. FIG. 6 shows by way of example that on a pole piece 19 which is S polarized, the adjacent face of the auxiliary permanent magnet 35 must be a pole S and the opposite face of magnet 35 a pole N. The auxiliary pole piece 37 of ferritic material will therefore by N polarized.
Another element of invention common to the different embodiments, concerns the coil 23 of the control electromagnet. The upper windings of this coil must be disposed on the highest possible level about the core 22, in the other words, the said windings must be as close as possible to the pole face 27. Thus, the parasitic magnetic flux emerging from the face 26' is considerably reduced.
A further element of invention, visible in FIG. 3, concerns the shape of the pole pieces 18 and 19, having the form of a funnel at the side of the entry of the pushers. In order to concentrate the magnetic control field to the selecting section, the pole pieces 18 and 19 are relieved according to the contour lines 39 and 40 a d the relievings are filled with a non-magnetic material 41 resisting to wear due to friction. FIGS. 4 and 5 show these same relievings, not filled, but covered each by the plate 36 already described. FIGS. 7 and 8 show a modification of this element of the invention. The concentration of the field is obtained by elongate openings 42, 43 provided in the pole piece 18 and 19, respectively. The openings must completely traverse the pole pieces, so that bridges 44, 45 are formed. The portions 46 and 47 must be of feeble cross section. Another solution, not shown, would be to eliminate this portion of the pole pieces and to replace them by slopes having the shape of a funnel, of nonmagnetic material fixed to the frame of the machine.
It is well known that during their travel between two selecting stations, a mechanical locking of the position of the pushers is required. Such locking may be obtained for example by a separating band 48 (FIG. 3).
The described device is particularly well suited for the selection of the knitting tools in a circular knitting machine. Upstream of each knitting system a selecting station is provided.
The device can also be used on fiat knitting machines, provided a selecting station is placed on each side of the cam plate. Alternatively, according to the diretion of movement of the carriage, the station following the cam plate is not supplied.
1. A selecting device for individual selection of knitting tools in knitting machines of very fine gauge, having a magnet with pole pieces and a control electromagnet which is polarized by electric pulses according to a given programme, the electromagnet causing selective deviation of the knitting tools towards one or the other pole face of the pole pieces of said magnet against which faces they are held by magnetic adherence, wherein the improvement comprises a core for said control electromagnet, said core being relieved at least at its end nearest the knitting tools and on the side of egress of the knitting tools, a coil for said control electromagnet, said coil being disposed on the highest possible level about said end of said core to reduce parasitic flux, said pole pieces being relieved in a portion on the side of the entry of said tools, supplementary magnets on the side of egress of said tools, and guiding partitions of non-magnetic material for said tools.
2. A selecting device according to claim 1, including hard metallic material deposited in the relievings of said pole pieces on the side of the entry of the tools.
3. A selecting device according to claim 2, in which the hard metallic material is non-magnetic and is resistant against wear due to friction.
4. A selecting device according to claim 2 in which the deposited hard metallic material has friction faces which form a channel without steps and discontinuities in the direction of movement of the pushers.
5. A selecting device according to claim 1, in which the pole piece faces 'bear a deposition of protective wear resistant material.
6. A selecting device according to claim 1, including a tool guiding plate having no discontinuity or steps, said plate being of hard metal material and extending over the entire length of a pole face.
7. A selecting device according to claim 1, in which one of said supplementary magnets is arranged over each pole piece of said magnet on the side of the egress of the tools to provide an auxiliary pole piece of opposite polarity to such pole piece of said magnet.
8. A selecting device according to claim 1, in which said guiding partitions are of bronze.
9. A selecting device according to claim 1, in which a selecting station is disposed on both sides of a cam plate of a fiat knitting machine.
10. A selecting device according to claim 9, in which the selecting station following at the rear of the cam plate in its reciprocating movement is not supplied.
(References on following page) 5 References Cited UNITED STATES PATENTS 6 FOREIGN PATENTS 883,432 11/1961 Great Britain.
Be uin et a1. 66-50 Degcerjay 66 5O WM. CARTER REYNOLDS, Pnmary Exarmner Ribler 6650 5 Ribler et a1. 66-50