US2692489A - Knitting machine - Google Patents

Description

Oct. 26, 1954 J. E. LYNAM EI'AL KNITTING MACHINE 4 Shets-Sheet 1 Filed Jan. 8, 1949 Z & 6L 5 M Invenloi y [ab y Oct. 26, 1954 J. E. LYNAM ETAL 2,692,489

KNITTING MACHINE Oct. 26, 1954 J. E. LYNAM ETAL I KNITTING MACHINE 4 Sheets-Sheet 3 Filed Jan. 8, 1949 Oct. 26, 1954 J. E. LYNAM ET AL KNITTING MACHINE 4 SheetsSheet 4 Filed Jan. 8. 1949 FIGS.

FIGS.

' I In ventors Patented Oct. 26, 1954 UNITED STATES PATENT OFFICE KNITTING MACHINE Application January 8, 1949, Ser'ia'l N0. 69,864

Claims priority, application Great Britain April 28, 1947 Claims.

This invention concerns knitting machines, especially Cottons patent and other straight bar knitting machines. In such machines it is customary to provide instruments which for certain operations, during which the normal knitting movements of the needles are modified, are moved to-occupy temporarily a position in which they co-operate with the needles. Examples of such instruments are the transfer points employed for fashioning and for producing a 'p-icot edge and like purposes, 'the welt hooks or other welting instruments employed in automatic welt turning apparatus, needle-deflecting instruments, and instruments for pressing selected needles or for causing selected needles to mispress. It is essential that such instruments shall be returned from their temporary attitude before the needles revert to their normal knitting motions otherwise the certainty arises that the needles will be smashed or damaged. The machine is timed to avoid such a mishap, but on the other hand since some of the machine movements are produced by springs (e. g. that hold cam followers against cams) there is always the danger that the required movements will not in fact be produced. It is this danger that the invention seeks to overcome or to minimise.

The invention therefore provides in a knitting machine, especially a Cottons patent or other straight bar knitting machine, having instruments movable to occupy, for a period during which the normal knitting cycle of the machine is modified, a temporary "attitude in which they co-operate with the needles or other knitting elements; a stop motion including apparatus for detecting failure of said instruments to revert from that attitude preparatory to or upon resumption of the normal knitting cycle, and/or for detecting failure of the needles or other elements to enter upon modified motions preparatory to or upon said instruments assuming said temporary attitude. It is to be explained that the expression stop motion as employed herein in the same broad sense that it is used in the trade, to include not only a motion (1. e. mechanism or apparatus) whereby the machine is actually brought to rest but also a motion whereby knitting operations or at least certain of them are suspended with a View to avoiding the ill effects that would otherwise accrue from the fault thus detected: furthermore, the expression failure is employed in a broad sense to include incipient failure.

The "invention further includes the provision in a knitting machine having at least one part movable to occupy, for a period during which the normal cyclic motions imparted to knitting elements of the machine are modified, a temporary attitude in which it would be fouled by said elements were they to pursue their normal motions, at stop motion including means responsive to a relative mispositioning of said part and-elements at the beginning or end of said period.

The invention. is primarily but not exclusively concerned with the machine forming the subject of Patent No. 2,428,514, The patent provides in 'a Cottons patent or other straight bar knitting machines, welt turning mechanism of the kind wherein welting instruments (or welt hooks) are inserted from the plain side of the needles to receive thread or thread kinks of an initial welt course, are retracted from the needles during the knitting of at'least a portion of the welt, are subsequently advanced to offer the initial welt course held by them to be transfixed by the rising needles, and are disengaged from the transfixed course by retraction; characterised by supports for engaging the initial course at least in the neighbourhood of the selvedge, and means for lifting said supports in relation to the welting instruments to facilitate the retraction of the latter from the transfixed initial course. These supports are constituted by instruments that register with and move upwards With the needles and they also serve to deflect spaced needles out of alignment with the rest in the restoration of the initial course of 'Welt. It will therefore readilybe appreciated that the normal needle motions require to be modified while the supports are in operation and that the supports must be returned to an ioperative position before the needles assume their normal motions otherwise a smash-up will result.

The above and other features of the invention are set forth in the appended claims and are disclosed in the detailed description given by way of example, of the particular embodiment illustrated in the accompanying drawings in which:

Figure 1 is a diagrammatical view of certain of the mechanism provided by Patent No. 2,428,- 514 together with electrical apparatus according to the present invention.

Figure 2 is a general cross sectional view of a machine incorporating apparatus according to this invention.

Figure 3 is a detail sectional view of auxiliary pressing mechanism incorporating a switch de- Figure 4 is a front view of :part of Figure 3.

Figures and 6 are front and side views respectively of a switch device for association with needle bar pressing mechanism.

Figures '7 and 8 are front and side views respectively of a switch device for association with control mechanism for knocking-over bits.

Figure 9 is a circuit diagram showing a modified arrangement.

In the specific embodiment described in the aforesaid patent and partly illustrated in Figures 2, 3 and 4 of the accompanying drawings, the support instruments I are carried by an instrument bar 2 which is mounted on the knocking-over bar 3 and is capable of being raised on the latter. Each support instrument constitutes an auxiliary presser and is formed with a loopengaging support ledge or shoulder. In the operation of turning the welt (i. e. restoring the initial welt course to the needles) the needle bar pressing truck 4 is shogged from the normal pressing cam 5 on to an auxiliary pressing cam 6 so as to modify the pressing movements of the needles I. The knocking-over truck 8 is likewise shifted from the normal knocking-over cam 9 to an auxiliary cam I8 so as to modify the normal movement of the knocking-over bits II and to advance the knocking-over bar 3 together with the auxiliary pressers I, so that the needles I are capable of pressing against said pressers instead of against the normal press-edge. These two trucks 4, 8, are shogged positively by means of truck-shogging bars I2, I3, respectively operated by truck levers I4, I5, and timin studs on a timing chain or any other patterning device.

They are returned in the opposite direction by springs 55, 66, respectively (Figure 1), when the machine resumes its normal knitting motions. Truck 4 and its bar I2 constitute a change-over device movable in one direction to produce the change-over from the normal knitting cycle and in the reverse direction to produce the reverse change.

After every second needle I has been engaged with the associated auxiliary presser I so that its beard is pressed and so that the said needle is deflected towards the front of the machine out of alignment with the other needles, the auxiliary pressures rise when the needles transfix the loops offered to them by the welt hooks I6. In this upward movement of the auxiliary pressures I and the needles I the welt loops are engaged by the ledges on the auxiliary pressers and are lifted, thereby permitting the welt hooks I6 to be disengaged from said loops by a sharp retractive movement. The auxiliary pressers I are caused to rise with the needles I by being themselves raised on the knocking-over bar 3. This movement is produced by a bar I! (Figures 3 and 4) slidable lengthwise of the knocking-over bar, and in order to shift this bar I! a truck I8 is shogged into engagement with a mis-pressing cam I9 by means of a truck-shagging rod 20 operated by a truck lever 2| and a stud on the timing chain, (or other patterning device), said truck-shogging rod 26 being returned in the opposite direction by a return spring I2I (Figure 1). Thus, a control device is provided comprising the bar I1, bell crank 38, rod 39, spring 40, truck lever I40, truck I8, rod 20 and truck lever 2|, which parts are movable in one sense to produce movements of the instruments I so that they occupy, for a period during which the needles perform their modified cycle of movements, a temporary attitude in which they cooperate with said needles, and in the reverse sense to pro- 4 duce movement of the instruments out of that attitude.

Since the return of the auxiliary pressers to their inoperative position is under control of the spring IZI just mentioned it will be understood that there is a danger that this spring may prove insufficient for the purpose required and that the auxiliary pressers I will remain in their raised position when the needles 'I revert to their normal knitting motions. In such an eventuality the beards of the needles I would catch the ledges of the auxiliary pressers I and would be smashed. In order to prevent this mishap the following apparatus is provided by the present invention comprising a stop motion which includes means responsive to incorrect relative movement between the change over device and the control device, for stopping the machine.

An electric motor 23 (Figure 2) which drives the machine is controlled by a circuit that includes not only a switch 24 capable of being broken automatically by means of a timing chain or equivalent device 25 but also a second switch (or relay switch) 26 operative by a relay circuit 2'? (Figure 1) so that when this relay circuit is energised the second switch 26 is broken and the motor 23 and knitting machine brought to a standstill. Incidentally, operation of this second switch 26 may serve to complete a subsidiary circuit that includes a telltale lamp 28. The relay circuit 21 includes a switch 29 (see also Figures 3 and 4) which is normally open but which is closed when the mis-pressing truck I8 is shogged to raise the auxiliary pressure; for convenience this switch 29 is referred to as the mis-pressing switch 29. It also includes two other switches 30, 3| that are themselves ar ranged in parallel and are normally closed. These two switches consist of a switch 30 (see also Figures 5, 6) which is opend when the truck 4 for the pressing movements of the needle bar is shogged to its auxiliary cam B (and therefore,

for convenience, called the needle pressing switch.

30) and a switch 3I which is opened when the truck 8 for the knock-over bar is shogged to its auxiliary cam I0 (and therefore, for convenience, called the knock-over switch 3|).

The sequence of operations is as follows:

1. Press rod I2 shogs to modify the pressing movements imparted to the needles I and to open needle pressing switch 30.

2. Knock-over rod I3 shogs to modify the movement of the knocking-over bits II and to open knock-over switch 3|.

3. Mis-pressing rod 20 shogs to bring the auxiliary pressers I into operation and to close mispressing switch 29.

At this phase, then the relay circuit 21 is open but it will be appreciated that if the timing or control mechanism which results in the pressing motions of the needle bar being modified preparatory to the auxiliary pressers being brought into operation, should fail, the pressing switch 30 will remain closed with the further result that upon the mis-pressing switch 29 being closed as the auxiliary pressers I are brought into operation the relay circuit 2'! will be completed and the machine brought to a standstill. This will obviate the smash-up that would unavoidably re-v sult were the auxiliary pressers I brought into operation at a time when the needles I still pursue their normal pressing motions.

When the machine resumes its normal knitting motions, by the needle bar and knock-over bar coming under control of their normal cams-5 and 9, and the auxiliary pressers l Ibeing lowered, the sequence 'o'foperations is as follows:

4. 'Mis-pressing rod returns under the action of spring 12! and opens zmis-pressingswitch 29.

5. Knock-over rod 13 returns under the action of spring 66 and :closes knoc'k 'overswitch "3 I.

6. :Press :rod 1 2 returns winder the action of spring 55 and closes the needle-pressing switch. 30.

At this phase the relay circuit 21 is "still open. Should, however, lllhe rod .21] :stick .(with the result .that the auxiliary pressers are left in .the operative position) the mis-pressing switch '29 will be le'ftclosed, so operation 5 .or 6 will result in .the .relay circuit 2'! 'being completed and the driving .motor 23 being 'brought -to .a standstill.

Therelay circuit'Z'l is a low tension circuit supplied by way of a transformer .32 (Figure 1'). When it is closed a relay coil 33 is energised thereby to operate the second switch 26 to break circuit 34 and to energise telltale lamp 28. Circuit-34 not only includes the automatic switchl24 but also a coil 35 of a relay "switch-.36 controlling the current supply to motor 23, so that when circuit 34 is broken and coil 35 is de-energised switch 36 opens.

The switches 29, 30, 3| may be snap-action switches such as micro-switches and suitable arrangements of these switches are shown in Figures 3 to 8.

Following the foregoing description the application of the invention to instruments other than the auxiliary pressers of Patent No. 2,428,514 will present no diiiiculty to the knitting machine builder. For example, the invention may be applied to ensuring that when transfer or picot points are brought into operation, the cyclic motion of the needles are suitably modified.

In Figures 3 and 4 the mis-pressing switch 29 is actuated through the medium of the auxiliary presser actuating bar l1, and adjusting bolt 31, the bar itself being actuated by bell crank 38, rod 39 and truck lever 40 carrying the truck l8; a spring I40 biasses the truck arm in the cam engaging position.

In Figures 5 and 6 the needle pressing switch 30 is actuated by the control rod l2 through the medium of adjustable lug or arm 4 I.

In Figures '7 and 8 the knock-over switch 3| is actuated through the intermediary of a cupshaped member 42 biassed by spring 43 and carried by the shogging rod I 3. The arrangement is such that additional movement of the rod I3 is permitted whilst maintaining the switch actuated but without further depressing the switch plunger 44.

In the arrangement just described, the pressing switch 30 and the knock-over switch 3| are in parallel with each other and are in series with the mis-pressing switch 29 and the transformer secondary so as to operate the second switch 26 and warning light 28 through a relay circuit 21.

In an alternative arrangement shown in Fig. 9 the warning lamp 28 is not employed and the mis-pressing switch 29 is in parallel with the needle pressing switch 30 and the knock-over switch 3! and these switches 33 and 3! are in series with a relay switch I26. The correct sequence of operations is as follows:

1. Press rod l2 shogs to modify the pressing movements imparted to the needles and to close needle pressing switch 30.

6. Press :rod 12 returns under the action rof spring 55 and opens the needle pressing switch 3.0.

"By comparison of this sequence .of operations with Figure '9 it will be observed :that at no time is the circuit open and hence the relay switch 126' (similar to switch 524, Fig. 1) is not actuated to stop the machine. However, should operations 71 or 2 fail, operation "3 immediately results in the circuit being opened; similarly should operation 4 ia'il, operations 5 or 6 cause the -circuit to be opened.

Having now described "and ascertained ithe fnature of our said invention and in what manner the same is to be performed, we hereby declare that what we cla im is:

1. In a straight bar knitting machine having knitting elements movable in a normal knitting cycle but also movable in a modified cycle, mechanism for effecting the change over between the two cycles of movement, instruments movable to occupy, for a period during which the said elements perform their modified cycle of movement, a temporary attitude in which they cooperate with said elements, and control mechanism for producing movement of said instruments into and out of their temporary cooperation; a stop motion including detecting apparatus for detecting an incorrect relationship between the kind of cycle performed by the knitting elements and the attitude of the instruments.

2. Apparatus according to claim 1, wherein the detecting apparatus comprises an electric control circuit for the stop motion and the two control switches in it which are operable in opposite senses, whereof one switch is operable by the change-over mechanism and the other by the control mechanism.

3. In a straight bar knitting machine having knitting elements movable in a normal knitting cycle but also in a modified cycle, a change-over device movable in one sense to produce the change-over from the normal knitting cycle to the modified cycle and in the reverse sense to produce the reverse change, instruments movable to occupy, for a period during which the said knitting elements perform their modified cycle of movements, a temporary attitude in which they cooperate with said elements, and a control device movable in one sense to produce movement of the instruments to cooperating attitude and in the reverse sense to produce movement out of that attitude; a stop motion including means responsive to incorrect relative movement between said devices for stopping the machine.

4. In a straight bar knitting machine having knitting elements movable in a normal knitting cycle but also in a modified cycle, a change-over device movable in one sense to produce the change-over from the normal knitting cycle to the modified cycle and in the reverse sense to produce the reverse change, instruments movable to occupy, for a period during which the said knitting elements perform their modified cycle of movements, a temporary attitude in which they cooperate with said elements, and a control device movable in one sense, upon movement of the first device to produce change-over to the modified cycle, to produce movement of the instruments to the cooperating attitude and in the reverse sense, upon movement of the first device to produce the change-over to the normal cycle, to produce movement of the instruments out of that attitude; a stop motion including means responsive to the aforesaid movements of either device being incorrect relative to movement of the other device.

5. In a straight bar knitting machine having knitting elements movable in a normal knitting cycle but also in a modified cycle, a change-over device movable in one sense to produce the change-over from the normal knitting cycle to the modified cycle and in the reverse sense to produce the reverse change, instruments movable to occupy, for a period during which the said knitting elements perform their modified cycle of movements, a temporary attitude in which they cooperate with said elements, and a control device movable in one sense, upon movement of the first device to produce change-over to the modified cycle, to produce a movement of the in- 8, struments to the cooperating attitude and in the reverse sense, upon movement of the first device to produce the change-over to the normal cycle, to produce movement of the instrument out of that attitude; a stop motion including a control circuit containing switches, controlled respectively by the two devices, for rendering said circuit operative upon aforesaid movements of either device being incorrect relatively to movement of the other device.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,571,765 Fels Feb, 2, 1926 2,067,146 Porter et a1 Jan. 5, 1937 2,101,048 Ischinger Dec. 7, 1937 2,183,575 Lieberknecht Dec. 19, 1939 2,428,514 Cooper et a1. Oct. 7, 1947 2,474,246 Hardison June 28, 1949 FOREIGN PATENTS Number Country Date 106,553 Great Britain May 31, 1917 634,797 Great Britain Mar. 29, 1950

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