Patent Publication Number: US-3875767-A

Title: Oscillation suppressing knitting needle

Description:
I Umted States Patent 11 1 1111 3,875,767  
 Kopal et a1. Apr. 8, 1975 [54] OSCILLATION SUPPRESSING KNITTING 1.221.806 4/1917 Scott 66/124 X NEEDLE 3.411.327 11/1968 Bcckcnstein 66/123 3.464.237 9/1969 Kohorn 66/121 51 inventors: Jaroslav K p Vladimir both 3.748.875 7/1973 510m a1 1. 66/123 of Liberec. Czechoslovakia 0 IGN PATENTS O APPL C F RE R 1 ATIONS [73] Assignee: S!atni Vyzkumny Ustav Textilni, 7  
  Liberec Czechoslovakia 945.027 1 /1963 Un ted K ngdom 66/124 1.145.150 3/1969 Umted Kmgdom 66/123 [22] Filed: Dec, 14, 1972 5119.779 6/1955 Italy 1. 66/123 1211 Appl. No: 315,162  
  Prinmry Examiner-Wm. Carter Reynolds Attorney, Agent. or FirmMich:1e1 S. Striker [30] Foreign Application Priority Data Dec. 14. 1971 Czechoslovakia 8673-71 [57] ABSTRACT [52] U.S. Cl. 66/123 A knming needle has cutouts forming one or Several [51] llit. C1 D041) 35/04 interconnected nan-0w slanted Shank portions adja [58] Fleld 01&#39; stlal&#39;ch 66/123. 121. 124 cem the but for suppressing Oscillations due to the impact of the butt on the raising and stitch cams of a [56] References Cited knitting machine UNITED STATES PATENTS 841.6711 1 1907 Elder 66/123 X 8 D&#39;awmg PATENIEDAPR 8 I975 mil 1 Ui Q R Aer PRIOR AR? PATENTEUAPR 81975 3875,76?  
 SHEET 2 3 PP/Oa? Aler 5 q a 2 4); FIG. 6 4 2 OSCILLATION SUPPRESSING KNITTING NEEDLE BACKGROUND OF THE INVENTION The present invention relates to an improvement of a latch needle of the type used in knitting machines.  
  It is known that a further increase of the speed of cir cular knitting machines, is prevented by the low resistance of latch needles against breakage. particularly in the region ofthe hook. It is generally believed that the reason for the breakage of the knitting needles is that the impact of the butt on the rising and falling cam track portion causes a pressure wave which results in longitudinal oscillation of the needle, and since the impacts are repeated, at a certain working speed of the circular knitting machine. a resonance effect takes place. which finally causes the breaking of the hook.  
  The developing of the resonance effect can be prevented by several measures. for example by braking the needle movement, which is disadvantageous for high speed knitting machines. and furthermore by producing sections in the needle which differ by mechanical and physical properties from each other. which may be effected by heat treatment. or by cutouts in the needle. In order to prevent or at least partly eliminate. breakage of the needle hooks. the different properties of the needle section are expected to vary the frequency or phase displacement of the occurring oscillations. However. this theory seems to be contradicted by tests. since the intervals between the impacts of the butts on the cams are so long that the oscillation in the needle is terminated before the following impact.  
  The breaking of the needle hook depends on the impact ofthe needle butt against the cam in the cam box. and on the high acceleration ofthe needle hook caused upon the transition to a raising or falling cam track. For a desired increase in the operational speed ofa circular knitting machine by at least 25 percent. the aboveexplained measures. which relie on empirical information. are not sufficient.  
 SUMMARY OF THE INVENTION It is one object ofthe invention to provide an oscillation suppressing knitting needle. particularly a latch needle of the type used in a circular knitting machine.  
  Another object of the invention is to prevent the breaking of knitting needles at high operational speed of the knitting machine.  
  Another object of the invention is to provide in the shank of a knitting needle. shank portions which have such a shape that oscillations caused by inpacts of the butt on cams. are suppressed.  
  With these objects in view. the present invention comprises a knitting needle whose shank has a predetermined height between the front and back edges. and which includes at least one shank portion slanted to the longitudinal direction of the needle. and having a width less than the predetermined height of the needle shank. Due to the provision of the narrow slanted shank portion. oscillations due to the impact of the butt on cams are suppressed.  
  Preferably. the width of the narrow slanted shank portion is at most one-third of the predetermined height of the shank. and the slanted shank portion defines with the back edge an angle of at least 50, and not greater then 130. The slanted shank portion, or several slanted interconnected shank portions. are produced by cutouts in the front and back edges forming between each other the narrow slanted shank portions. The depth of each cutouts is greater than half the height between the front and the rear edges so that apexes of the preferably triangular cutouts overlap in a direction transverse to the longitudinal direction of the shank. The cutouts may also be segment shaped.  
  In a preferred embodiments, a second slanted narrow shank portion extends parallel to the first slanted shank portion, and a third narrow shank portion connects the parallel slanted shank portions and is slanted in a direction opposite to the parallel slanted shank portions. so that a greater oscillation suppressing effect is obtained.  
  Knitting needles constructed in accordance with the invention are subjected to a minimum of breakages. Since the manufacturing of the knitting needles in accordance with the invention is not substantially more complicated than the manufacture of standard knitting needles, the advantages of the present invention. namely better quality of the knitted fabric. and higher productivity of the knitting machine. substantially exceed the disadvantage of a more complicated manufacturing operation.  
  The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself. however, both as to its construction and its method of operation. together with additional objects and advantages thereof. will be best understood from the following de scription of specific embodiments when read in con&#39; nection with the accompanying drawing.  
 BRIEF DESCRIPTION OF THE DRAWING FIG. is a side view illustrating a latch needle according to prior art;  
  FIG. 2 illustrates the mounting of cylinder needles in a needle cylinder;  
  FIG. 3 is a side view of a series of knitting needles moving through positions I to V during the formation of a stitch;  
  FIG. 4 is a schematic view illustrating the cooperation between the butts of the knitting needles and the raising and stitch cams of the cam box off the machine;  
  FIG. 5 is a fragmentary side view illustrating one embodiment of the knitting needle according to the invention;  
  FIG. 6 is a fragmentary side view illustrating another embodiment of the invention;  
  FIG. 7 is a fragmentary side view illustrating a further embodiment of the invention;  
  FIG. 8 is a side view illustrating the blank which can be used for manufacturing a knitting neelde according to the invention;  
  FIG. 9 is a side view, and FIG. 9a is a plan view illustrating the formation of a slot in the mounting portion of the needle;  
  FIG. 10 is a side view illustrating the mounting of the latch; and  
  FIG. II is a side view illustrating a knitting needle according to a further modified embodiment of the invention.  
 DESCRIPTION OF THE PRIOR ART As shown in FIG. 1, a latch needle I has a shank 2 which has at one end the hook 3 and at the other end a tail portion 4 formed with a butt 5. The hook 3 merges into the mounting portion 6 in which a latch 7 is mounted for angular movement on a rivet 8 between positions for opening and closing the book 3. Rearward of the reinforced mounting portion 6, a narrow stem portion is formed. which permits complete retrac tion of the latch 7 with spoon 9 to an open position.  
  As shown in FIG. 2, knitting needles I are mounted for movement in vertical milled channels I] which are provided in the needle bed 12 ofthe cylinder ofa circular knitting machine. The channels 11 are separated by guide ribs 13, which guide the needles 1 during recipro cating movement in the channels 11. In some knitting machines, lammelar strips are inserted into the needle bed body, which perform the function of the guide ribs 13. Since the needle beds 12 of most knitting machines are arranged in a vertical or slightly slanted position, the movement of the needles in forward direction to the highest position is referred to as lifting, and the opposite movement as lowering.  
  The upper ends of the guide ribs 13 form a cast off surface 14. in which a newly fed yarn is caught so that it can be pulled by the hook of the needle through an old loop, as schematically shown in FIG. 3. Position I shows the old loop 15 in the hook 3 of the latch needle 1, when the latch needle I is raised by a raising cam I8, as shown in FIG. 4, the old loop 15 opens latch I and slides down on the stem 10, as shown at 11. When the needle is lowered by a stitch cam I9, see FIG. 4, it as sumes the position III in which the old loop slides under the latch 7, while the new yarn 16 is caught by the hook 3. During further lowering ofthe latch needle 1 below the cast off surface 14, position IV, the new yarn 16 forms a new loop which is pulled through the old loop I5 so that a new stitch I7 is formed. The latch needle I is than freed and is slightly raised by the pull exerted by the new stitch 17, as shown at V so that the needle is again in the initial position shown at I.  
  As noted above. raising cams I8 and a stitch cam 19 are shown in FIG. 4 for guiding the schematically indicated butt 5&#39; to higher and lower positions during rotation of the needle cylinder. The position of a knitting needle I is shown in the left portion of FIG. 4.  
  The latch needles I move together with needle bed 12 against the slanted surfaces of the raising cam 18 and the stitch cam 19, and at a speed of 0.5 to I m/sec. The cam track faces of the cams l8 and 19 are usually planar and form usually an angle of 50 with the direction of movement ofthe latch needle 1. The needle butt 5&#39; abuts the slanted cam track portions of raising cam I8 or stitch cam I), so that an impact is exerted for raising and lowering the knitting needle The impact can be measured. and is many times the force required for lifting or lowering the knitting needle I. The impacts of the butts 5, or 5&#39; in FIG. 4, cause the aboveexplained longitudinal oscillation in the shank 2 of the latch needle I. The impact is transmitted through the shank 2 to the hook 3 which is subjected to fatigue and breaks at the root 20 of the hook 3. Such fatigue and consequent breaking of the needle hooks 3 is to be prevented by the invention.  
 DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 5 illustrates a portion ofa knitting needle in accordance with the first embodiment ofthe invention. In this embodiment, the shank 22 of the latch needle 21 is formed with two opposite cutouts 23, 24 in the front edge fand back edge 26 of the shank 22. The substantially triangular cutouts 23, 24 overlap a transverse dis tance .I&#39;. The first cutout 23 is directly adjacent the needle butt 5, and the second cutout 24 adjacent the first cutout 23 in the direction toward the hook 3. The two triangular cutouts 23 and 24 form together the narrow slanted shank portion 25 whose width is at most onethird of the height z of shank 22, and whose corresponding width is indicated at y (y s z/3 The angle or formed by the narrow slanted shank portion 25 and by the back edge 26 of the shank 22, is within the range of from 50 to I30 so that the shank obtains a certain resiliency, which is capable of reducing the accelera tion upon impact of the butt 5 on a cam track face. The height of shank 22 rearward of the narrow slanted portion 25, may either be the same as the width of the narrow slanted shank portion 25, as shown in FIG. 5, or the original height 2 of shank 22 may be retained, as shown in FIG. 7.  
  As shown in FIG. 5, in addition to the pair of triangular cutouts 23, 24 which form the slanted narrow shank portion 25, another slanted shank portion 30 is formed by a cutout 31 in the shank and the cutout 31 forms also a straight shank portion 32 extending along the back edge 26 and having a height less than the height a of the shank 22.  
  Since the narrow slanted shank portion 25 may also in some cases be subject to fatigue and breakage, it is possible to strengthen the slanted narrow shank portion 25 by a suitable heat treatment, known to those skilled in the art. The heat treatment may consist in local annealing by means of a gas flame, or heating by highfrequency oscillationsor by immersing into molten lead. An annealing method in which the needles are immersed in hot cylinder oil, or in a hot air furnace with an inert atmosphere can also be used. Such heat treatments are well known, and it is only required to localize the heat treatment to the stressed shank portions.  
  In order to increase the final effect of oscillation suppression, the shank 22 can also be formed with several successive narrow slanted shank portions 25, as shown in FIG. 6. The first narrow slanted shank portion 25 is formed by the two triangular cutouts 23, 24, as described with reference to FIG. 5, and the following section of shank 22 is again provided with two identical triangular cutouts 23a, 24a which together from a narrow slanted shank portion 25a. The remainder of the shank has again the normal height.  
  The oscillation suppressing effect of the knitting needle of the invention, can be further increased by pro viding a second narrow slanted shank portion 25a par allel to shank portion 25, and connecting the parallel narrow slanted shank portions 25, 25a by an oppositely slanted narrow slanted shank portion 27 The shank portions 25, 25a and 27 preferably have, as shown in FIG. 7. the same width. The manner of manufacturing the needle according to the invention is shown in FIGS. 8 to 10. As shown in FIG. 8, a needle blank la is stamped out of a metal sheet, the hook 3 being later formed in a separate operation. The mounting portion 6 is provided with a slot 28 for receiving the latch 7, 9, as shown in FIGS. 9, 9a and 10, the latch 7, 9 being also formed in a separate operation. The latch is secured to the mounting portion 6 by a punched rivet. Thereupon, the cutouts 23, 24 are stamped out forming the slanted narrow shank portion 25. It is, however, possible to make the cutouts 23, 24 in the same operation by which the blank shown in FIG. 8 is formed. FIG. II II- lustrates a complete needle in which the shank portion 22 is formed forwardly of the butt 5 with two cutouts 23 and 24 in the manner as described in connection with FIG. 5. The needle shown in FIG. 11 differs from the embodiment partly shown in FIG. 5 in that the shank portion 22 forwardly of the cutouts has the same height as at the tail portion 4 of the needle. FIG. 1] illustrates also the usual hook 3 at the front end of the needle as well as the latch 7 mounted for angular movement on the rivet 8 in the mounting portion 6 of the needle.  
  It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of knitting needles differing from the types described above.  
  While the invention has been illustrated and described as embodied in a knitting needle provided with a narrow slanted shank portion for suppressing oscillations caused by impact of the needle butt on cams, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.  
  Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that. from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims What is claimed as new and desired to be protected by Letters Patent is set forth in the following claims.  
  1. Oscillation suppressing knitting needle having a shank with a front edge and a back edge, a hook at one end and a butt at the other end and projecting from said front edge, said shank having a predetermined height between the front and back edges at least in the region of said butt and including a first substantially triangular cutout extending from said front edge into said shank adjacent said butt, and a second substantially triangular cut-out extending into said shank from the said back edge at a location longitudinally adjacent to said first cut-out and spaced from said first cutout in direction toward said hook, said cut-outs forming between themselves a slanted resilient shank portion having a width considerably smaller than said predetermined height and having substantially parallel edges slanted to said front and back edges so that oscillations due to the impact of said butt on cams are suppressed.  
  2. A knitting needle as claimed in claim 1 wherein the width of said slanted shank portion is at most one third of said predetermined height.  
 3. A knitting needle as claimed in claim 1 wherein said slanted shank portion defines with said back edge an angle of at least 50 and at most l30.  
  4. A knitting needle as claimed in claim 1 wherein the depth of each cutout is greater than half the height between said front and rear edges so that said triangular cutouts overlap in a direction transverse to the longitudinal direction of said shank.  
  5. Oscillation suppressing knitting needle having a shank with a front edge and back edge, a hook at one end, and a butt at the other end, said shank having a predetermined height between said front and back edges at least in the region of said butt, and including a first shank portion slanted to the front and back edges, a second shank portion parallel to said first shank portion, and a third shank portion connecting the parallel slanted shank portions and being slanted to said front and back edges oppositely to said parallel slanted shank portions, all of said slanted shank por tions having the same width which is less than said predetermined height.  
  6. Oscillation suppressing knitting needle having a shank with a front edge and a back edge, a hook at one end and a butt on the other end, said shank having a predetermined height between said front and back edges at least in the region of said butt, and including a shank portion slanted to said front and back edges and having a width less than said predetermined height, and a cutout in said front edge of said shank adjacent said slanting shank portion and forming a second oppositely slanted shank portion having a width less than the predetermined height, said cutout also forming a straight shank portion extending along said back edge and having a height less than said predetermined height.  
  7. A knitting needle having a shank with a front and back edge, a hook at one end, and a butt at the other end, said shank having a predetermined height between said front and back edges at least in the region of said butt, and having cutouts in said front and back edges whose depth is greater than half of said height between said front and back edges so that said cutouts overlap in a direction transverse to said edges, said cutouts forming between each other a first narrow shank portion slanted to the front and back edges at an angle within the range of 50 to and having a width of about one-third of said height, a second narrow shank portion substantially parallel to the first shank portion, and a third narrow shank portion connecting said first and second shank portions and being slanted to said front and back edges oppositely said parallel shank portions.  
  8. Oscillation suppressing knitting needle having a shank with a front edge and a back edge, a hook at one end, and a butt at the other end, said shank having a predetermined height between said front and back edges at least in the region of said butt and including two substantially triangular cutouts respectively extending from said front and back edges into said shank, said cutouts being spaced in the longitudinal direction of said shank so as to form between said cutouts a first slanted shank portion having substantially parallel edges slanted to said front and back edges, said first slanted shank portion having a width considerably smaller than said predetermined height, a second slanted shank portion parallel to said first slanted shank portion, and a third shank portion connecting said parallel slanted shank portions and being slanted to the front and back edges opposite to said parallel slanted shank portions so that oscillations due to the impact of said butt on cams are suppressed.