US2016870A - Knitting machine - Google Patents

Description

Oct. 8,i 1935. F, MEM/ALD A 2,016,870 l KNITTING MACHINE vFiled vMay 21, 1952 2 Sheets-Sheet l f Oct. 8, 1935. F. MEIWALD 2,016,870

KNITTING MACHINE Filed'May 21, 1952 2 sheets-sheet '2 Patented Oct. 8, 1.935

UNITED r,STATES KNITTING MACHINE Franz Meiwald, Vienna, Austria Application May 21, 1932, Serial No; 612,688 In Austria August 7, 1931 5 claims.

My invention relates to improvements in devices for producing tubular coverings such as are used for instance for electric conductors or other strand elements.

It has already been proposed to surround conductors, particularly electric cables, instead of with the usual braided covering, with a knitted covering so as to protect the insulation as well as for insulating purposes, since a considerable saving in material and in operating timeis thus attained in view of the greater efciency of the knitting machine as compared to the high-speed braiding machine. Such a device and products manufactured with it are disclosed for instance in my U. S. Patents Nos. 1,814,324 and 1,936,519,

J on which the present invention is an improvement. As the saving increases with increasing length of the loop, the tendency has been therefore to increase the loop length as far as possible.' This, howeverV impairs the appearance of the tubular covering, since the rows of wales spaced apart a distance equal to the length of the loops project from the tubular covering, thus rendering the surface irregular. This is particularly the case, if columns of knitted loops are for special reasons arranged spirally such as the diso closures in my aforementioned patents show, as

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the loops then form, between adjacent Wale rows, the cords for a cylindrical surface formed by the spiral rows of wales, and these loops therefore lie lower than the wale rows, so that the latter become undesirably prominent.

In circum-knitting cores such as electric conductors or similar strand elements with any form -.0f knitting, it is of great importance that the speed at which the core is supplied to the knitting head be always in suitable relation to the speed at which the cireum-knitted fabric is produced by the knitting head, since .otherwise either the fabric becomes too loose and fails in its protective purpose, or it becomes too vtight and thus causes breakage of its constituent threads. While it has been proposedin the prior art to positively gear the supply device `for the `core t0 .i the rotary elements of the knitting head, to secure a certain desired ratio of the operating speeds of these elements, such positive gearing is insuflicient since the knitting process involves in,

addition ,a number of variable functions which ijustment of, the speed ratio between the core readily may upset'the desired effect of vsuch fixed l (o1. fia-s) feed andthe production of the knitted fabric which may be readily varied at will to suit the prevailing knitting conditions and by which any desired clcse or loose fitting of the knitted covering to the core can be attained.

-While I have illustrated and described my invention with reference to the preferred form of circum-knitting a core with a covering in which the bights of the loops of adjacent courses form a zigzag line following the direction of the loop .10

courses, the particular speed ratio control atrangement between the core speed and the knitting speed shown may be applied without change in principle to the ordinary single thread knitting of acovering around a core in which case 15 it is likewise important to maintain the proper speed ratio.

The invention is represented in Figures 1-7. Figure-1 discloses one of the designs which represents, according to the invention one of the 20 different possible bonds of loops, knitted around a core. Figure 2 shows diagrammatically the knitting devices with the needle cylinder andthe corresponding cam rings for producing covering for a core according to Figure 1. Figure 3 rep- 25 resents diagrammatically the knitting machine, with the knitting head cooperating with the device over which the objectA passes which is to be surrounded with a tubular covering. Figure 4 represents an end elevation of the shea've I3 of 30 Figure 3. Figure 5 represents a view Ipartly in longitudinal section and in larger scale, of the type of knitting head shown'in Figs. 2 and 3 provided with two cam rings. Figure 46 is a top view of one han of lthe knitting head, Figure 5, 35

the other half representing a transverse sectional view taken on the line 6-6 of Figure 5, and Figure 7 represents 'the development of a' cam ring particularly adapted to produce the tubular covering involved in Figures 1 and 2.

In the design shown in Figure 1, adjacent loops `of each row, while of equal lengths, have long floats between them, and between these loops extend partway the loops of the next succeeding row,

overlying with their long floats" 8 the loops oi' the p45 preceding row so as to attain theeifect described and claimed'speciflcally in my U. S. Patent No. 1,947,302. For instance as, shown in Figure 1, the loops of succeeding rows are staggered an amount equal to half the length of the loops so 50. y that the altemately succeeding loop heads 9, I0

of the'v two rows form a much deeper zigzag line Il around core 'L4 'I'he cam ring 4 (Figure 2) has accordingly two grooves 5 and 6 each with two high points. Circumferentially successive high points are displaced. by Successive needles in the bed, are guided alternately in the upper and lower groove. The knittingl operation. is carried out at the same time with four-v threads, which pass over thread guides displaced 90 (not shown in Figure 2l. In the diagram, Figure 2 only two needles are visible and the threads are not shown. This matter is, however, clearly illustrated in` Figures l, 4, and. 5 of my Il; su Patent No. 2,006,275, the application for which 'was led of even date with the present application.

Other methods oi knitting may also enr ployed in order to attain an arrangement oi? `staggered loops. With the aboveementio-nocl rangements, it is possible to knit several rowsof loops at the same time, so that the circuinu ferentlally successive binding poli/itt',y oi' successive rows of loops are staggered. All or a portion ofthe binding points of the variousrows of loops may, however, be also staggered with respect to the other rows iii-leona It is also possible to to obtain other kinds of interlacngs by the o! two or more caniv rings having cam grooves with one or more rises, the cam. rings; being die posed in axial alinement one above the other, and.

oil'set in circumferential direction as shown in my aforementioned Patent No. 2,006,275 so that in axial direction the peaks of one groove register with the valleys of the groove 'oi the adjaceirit ring, similar to the manner shown in` Figure ol the present application, except that thetwo grooves there shown are disposed on, the saine ring. The cam paths should have in that case at their low points a. straight portion. similar to the manner shown. in Figure 2. In this manner a formation of superposed loops is obtained In order that undue yarn tensions may not occur during the knitting which might cause a breakagelof the yarns, the central core I2 is fed. into the knitting head at a speed which differs i slightly from the speed with which the tubular covering leaves the Iknitting machine. In this way yarn tensions cannot occur as a result of the thread adhering to the' central core passing through the knitting device at a high speed. In the case of e. smgle-thread covering with loops ,positioned parallel with the core axis, the core advances the length of a. loop at each revolution of the needle cylinder or cam ring. In the case of a multiple-thread covering with the loops posi-g tloned in parallel with the core, the core advances for each rotation ot the needle cylinder as many times the length oi' a loop unit as there are threads distributed on the periphery o! the core. In the case o! a knitted tubular .covering with l loops which are positioned at an angle to the core 4 axis, as is shown in my aforementioned patents, the feeding speed of the core varies in accordance with the cosineoi this angle. In order to maintain the prescribed speed of the core, the core over a reed control device which is positlvl timed with relation to the knitting head and cam speed to suit the kind of knitting on han 'This ahead of the knitting head in the direction in which the core moves, so that it controls the core feed into the knitting head. It may, however, be also arranged in similar manner behindl the knitting head or the movement of the core may in similar manner be etl'ected at both points.

In Figure 3, which shows the' core speed control device ahead ot the knitting head. I2 denotes the central core to be provided with a tubular covering. 'I'he core to be covered passes over a sheave Il and through the knitting-device Il '33, is provided with a fine thread device is preferably disposedA several timos around sheave I3 to secure a better 5 gril@D The knittinghead is shown partly in section in Figure 5., 25 denotes the needle cylinder, 26 the knitting needles, 2l the upper and, 2B the lower cano ring. The position of both cam rings is 10 adjustable with the aid of the shoulder screws 2E, tif 'taking into the upper earn ring 21, and 305, 3i taking into the lower cam ring 2E through Vertical slots on opposite sides of the casing 34. This provides for the rough verticali adjustment l5 of the com. rings. Circumierential adjustment of the rings is possible by the saine means, for instance for cam 2l, by removing shoulder screws 25 and 3l suilioiently to disengage the cam ring, whereupon the latter may be turned 20 and the screws' 2Q and 3l be reinserted and. tightened/la With, the number of diametrica-lly opposed screw holes/,in the cani rings spaced suitable peripheral distances apart, the cam rings may thus be conveniently periphernlly adjusted. 25

The needle cylinder is rotatably mounted in cani ringe 2 and 28 and vertically supported on its hcllowdriving shaft 32 with which it is removably coupled. by means ci a square end.i 32. In order to heid the needle cylinder firmly in coupled engagement, and to avoid. vertical vibrations of the cylinder at its high operating speeds, a coil spring 25u is provided on the lower, slender portion of the cylinder, which spring is in engagement at its lower end with the lower cylinder 35 portion., and, abuts at its upper end through a ball bearing 46 against a shoulder provided in the interior of the cam ring housing 34'. Thus the needle cylinder is always firmly pressed against the end of its driving shaft 32. This 40 latter shaft is journalled in a stud 49 which forms part Vof the machine frame (not shown) and which thus rotatably supports the entire knitting head.

Thecasing 34' which contains the cam rings 45 has a suitable drive connection with the sleeve 33 of a cam ring driving gear 33, the latter being also rotatably supported on the previously mentioned machine frame stud 49 by means of ball bearing vI8, so that it can rotate independently 5o of the needle cylinder. As Fig. 3 shows, cam ring gear 33 is driven by the same bevel gear, Il which operates shaft 32 of the needle cylinder, but at the desired speed ratio with respect to the shaft 32, produced by gear train 50 in Fig. 3.

The lower end oi cam casing 34', ahead of the point of its driving engagement with drive sleeve with which it is threaded into an adjusting sleeve Il which slides over the end of sleeve 33. This sleeve 34 no serves to .eiect a ilne vertical adjustment oi the cam rings and thus of the eiective needle throw with respect to the upper rim 25a of the needle cylinder over which the knitted loops bend before they slide into the interior of the cylinder in the 65 usual way. 'I'he coarse vertical adjustment of the cam rings by means of screws/ZI-'II has already been mentioned -above and serves a. similar purpose. By these coarse and 'tine adjustments the vlength of the loopsiormed-by the 70 l lneedles can' be vcryaccurately adjusted within o! the head, but also upon the length of the loops, `this coarse and iine regulation of the loop length forms a very important and critical factor in adapting the knitting 'speed correctly to the prevailing speed at whichthe core is fed into the knitting head. Such convenient adjustment between the two speeds is, of course, not possible merely with the gearing between the core speed and the cylinder speed as shown at I5-23 and at 50 in Fig. 3 which is more or less fixed for the` time .being and constitutes in reality only an approximate relation between the two speeds. In order that the needle cylinder may be easily removed it is held down, as shown in Figs. 5 and 6, by means of a bayonet joint ring 35 within which adjustment sleeve 34 can be turned for adjustment in the manner shown in Fig. 5. This ring 35 is provided with two diametrically oppositely disposed circular slots 36, of which one is clearly shown in Fig. 6, and in each of which one of the thumb screws 3l is located. These screws are threaded into a ring 38 which is socketed on and suitably attached to sleeve 33 of gear 33. By loosening thumb screw 3l, and by turning ring 35 a short distance in clockwise direction (Figure 6) until slots 36 are out of range of screws 3l and are brought into registry with clearance notch 39 in the ring, the latter can be lifted off its seat in portion 38 and the knitting head, including the needle cylinder and cam ring housing 34 can be pulled out of sleeve 33a. Spring 25a previously mentioned assists 1n this lifting operation. When screws 31 tighten the bayonet ring 35 down, fine adjusting sleeve 34 is at the same time locked in its adjusted position against ring 3d.

This knitting head and the core feeding mechanism as described and shown may serve for any suitable form of knitting, for instance such as is shown in Figures 1 and 2, the two separate cam rings 2l and 28 representing in particular 'the cam arrangement of Figure 2, except for the separation of the rings in Figure 5, which as appears from the foregoing description merely facilitates the( relative positioning of the cams. As soon as the cams in Figure 5 are adjusted and iixed in their desired relative positions, the cam system operates as shown in and described with respect to Figure 2, and produces the knitting shown in Figure l.

A further suitable design of thegnachine consists in designing the cam ring for the operation of the knitting needles with diie'rent angles of the needle advancing and retracting groove portions With respect to the central axis of the system. The cam groove is so designed that the angle of inclination of the needle retracting groove branch to the axis of rotation of the knitting device is smaller than the inclination of the angle of the needle advancing groove branch to the same axis. This design of the cam groove has the advantage that more cam elements may be accommodated within a given peripheral .length of the cam cylinder than` has hitherto been possible, so that the number cit/'operations for a needle is increased accordingly, which renders the system most eicient; If one is, however, not bound to the diameter of the cam ring cylinder, its diameter, while maintaining the output, may be .decreased in accordance with the steepness of the angle of the needle retracting groove branch. In this way, a decrease of the weight of the knitting head is brought about which effects on the one hand a saving in material, so that lighter supporting members may be provided, and on the other hand advantages are attained in operation, Vowing to the reduced weight of the gyrating masses. The invention is applicable to knitting machines of every description, for instance to machines with two or more systems of cam grooves. The invention is equally 5 applicable to other textile machines with cam groove controls.

.A cam groove with differently inclined branches is shown diagrammatically by way of example in Figure v'7 which shows the development of a cam 10 groove in the plane of the drawings.y The cam groove 42 has four needle advancing paths and` four idling paths. The cam ring moves in the direction of the arrow 43. The `angle of the needle advancing groove branch to the horizon- 15 tal line amounts to 42 and the angle of the needle retracting groove branch amounts to 52. The needles will, consequently, advance slowly and retract rapidly.

Central cores, such as electric conductors, cables 20 y with or without lead sheaths, flexible cores for telephones, rubber tube insulated co-nductors, cab-tire metal sheathed wires may be provided with a tubular covering on the above-described knitting machine: f f

The knitted tubular covering applied to the insulation of the -conductor may be according to the invention improved by calendering and treating it with conventional dressing agents such as gelatine, solutions' of starch, sugar or the like, by 30 machines not shown here, as soon as it leaves the knitting machine. The knitted tubular covering is thus an excellent substitute for a braided tubular coveringl with dressing, since in the present case the dressing agent penetrates the com- 35 for operating said needles, means positively 45 geared to said knitting head for moving said core through the knitting head in xed speed relation to the operating speed of the head, and means for adjusting in axial direction the distance between said cam ring and the top rim of said 50 needle cylinder for adjusting the eifective length of the looping stroke of. said needles to correlate the speed at which the knitted covering is produced to the core speed.

2. In a machine for knitting a covering around 55 a core, a knitting head including a needle cylinder having needles and axially spaced cam rings surrounding said cylinderfor operating said needles, means positively geared to said knitting head for moving said core through the knitting 60 head in fixed speed relation to the operating speed ofthe head, and means for adjusting in axial direction the distance between said cam rings and the top rim of said needle cylinder, for adjusting the effective length of the looping 65 stroke of said needles to correlate the speed at which the knitted covering is produced to the ing said core through the needle cylinder in nxed 75l` ting head, and means for adjusting said cam rings in axial direction with relation to one another and to the top rini oi said needle cylinder, said means comprising a cam ring carrier supported within said base and set screws in said rings adapted to be tightened against said carrier for coarsely adjusting said rings :in axial direc-- tion, and a sleeve finely threaded onto said carrier for supporting said carrier on said/base and for axially displacing said carrier `with relation 'to the top'rim of said needle cylinder, to coarsely and finely adjust the effective length of the looping stroke of said needles, for correlating the speed at which the knitted covering is produced to the speed ofthe core. i

4. In a machine for knitting a covering around a core. a knitting head including a base, a. needle cylinder disposed within said base and having needles and axially spaced cam rings surrounding said cylinder for operating said needles, means positively geared to saidf knitting head for feeding said core through the needle cylinder in ilxed speed relation to the operating speed of the knittingA head, and means for adjusting said cam rings in axial direction 4with relation to one an-` other and to the top rim of said needle cylinder, said means comprising a cam ring carrier supported within said base and set rscrews in said i rings adapted to be tightened against said carrier'v for coarsely adjusting said rings in axial direcno1 6,870 l speed relation to the operating speed of the knittion, and a sleeve finely threaded onto said carrier for supporting said carrier on said hase, and for axially displacing said carrier with rel-ation to the top rim fol said needle cylinder, to coarsely and iinely adjust the effective length of the looping 5 stroke of said needles, for correlating the speed at which the knitted covering is produced to the core speed. and a bayonet joint for attaching said threaded sleeve to said base.

5. In a machine for knitting a covering around l0 a core, a knitting head consisting of a needle cylinder having needles and cam rings surrounding said cylinder foroperating said needles, a housing :for said cam rings, a supporting stud 'for rotatably supporting said needle cylinder and 15 said housing and a spring between said cylinder .and said housing for maintaining the desired relation between said two elements in axial direction, means positively geared to said needle cylinder and to said cam ring housing for moving said 20 core through the knitting head to correlate the core ieed to the operating speed of 'the head, and means for coarsely and nely adjusting said cam rings in axial direction with respect to the top rim of said needle cylinder for setting the efl'ec- 25v tive length of the looping stroke of the needles, topermlt-adjustment of the knitting speed of the knitting head with relation to the core speed, and means for locking said axial cam ring adjustments. 30

FRANZ MEI'WALD;

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