US2142745A - Mechanism for producing welts on straight bar knitting machines - Google Patents

Description

Jan. 3, 1939. L, H, coLTog. 2,142,745

MECHANISM FOR PRODUCING WELTS ON STRAIGHT BAR KNITTING MACHINES Filed June 15, 1938 s Sheets-Sheet 1 L717 Fig. 2.

Jan. 3, 1939. L. H. COLTON 2,142,745

MECHANISM FOR PRODUCING WELTS ON STRAIGHT BAR KNITTING MACHINES Filed June 15, 1938 5 SheetsSheet 2 INVENTOR.

A TTOENEY Jan. 3, 1939. L. H. COLTON 2,142,745

MECHANISM FOR PRODUCING WELTS ON STRAIGHT BAR KNITTING MACHINES Filed June 15, 1938 5 Sheets-Sheet '3 Fig.10.

INVENTOR Patented Jan. 3, 1939 I PATENT OFFICE MECHANISM FOR PRODUCING WELTS ON STRAIGHT BAR KNITTING MACHINES Lewis Henry Colton, West Bridgford, Nottingham, England Application June 15, 1938, Serial No. 213,899 In Great Britain June 18, 1937 14 Claims. (01. 6696) This invention comprises improvements in mechanism for producing welts on straight bar knitting machines, such as machines of the Cottons patent type.

. More particularly the invention relates to means for producing a welt in a fully automatic manner and refers to welting mechanism of the kind wherein welt hooks are operated from above the frame needles to receiveloops released from said needles or extending between spaced needles and subsequently after the formation of the requisite welt to return such loops to or place them on the needles, said welt hooks being provided on a welt bar carried by depending arms that are guided against undesirable lateral movement and said welt bar being operated from a cam shaft located above the needle row.

In welting mechanism of this kind, as hitherto operated, the welt hooks are lowered at the front side'of the needles (i. e. at the bearded side thereof which is at the back of the line of needles from the machine operator) in contact with the presser bar and serve to press the beard of every second needle, so that as the needles are lowered every second loop is cast off. The welt hooks now move towards the front of the machine, over the heads of the needles so that each hook is entered into a loop that extends between say two even needles over two knocking-over bits, and upon further downward movement of the welt hooks the point of each hook is brought below the loop that said hook engages, so that said loop is securely landed in the hook. In this mode of operation it is essential that the welt bar, on which the hooks are mounted, be so adjusted that the hooks pass across the line of needles in close proximity to the needle heads, and this is diflicult, particularly as it is customary to adjust the needle bar to govern the'quality of the fabric and each such adjustment throws the welt bar out, of adjustment. As a result, there is alwaysa danger that the welt hooks will foul the needle heads (which are not always perfectly aligned) or will pass over them at too great a distance from them and there is a danger'of needle breakage by reason of faulty positioning of the welt hooks. Moreover, the use of the welt books as pressing-instruments itself involves difficulties in the design and adjustment or setting of the hooks.

An object of the invention is to simplify and render particularly efficaciou's automatic weling by the employment of mechanism of the kind referred to. The present invention provides .a method of producing a turn-over welt on a straight bar knitting machine by the employment of welting mechanism of the kind. referred to, wherein the thread of the first course is prevented, by means independent of the welt hooks, from being engaged in the beards of spaced needles with which the Welt hooks .co-operate. Selected or predetermined thread loops, to be received by the welt hooks, may be released from the needles by said means. Alternatively, the thread for said initial welt course is laid on or received by selected or predetermined needles only, so as to provide between said selected needles floating thread portions adapted to be taken up by the welt hooks and carried thereby during the welt production.

Viewing the invention from another aspect same comprises a method of producing a turnover welt by the mechanism previously mentioned wherein the loops to be taken by the welt hooks are released or pressed-off from selected needles (e. g. alternate needles) by pressing said selected needles while said hooks are maintained out of contact with and above the needles and during the downward movement of the needle bar, the hooks being subsequently lowered to receive the released loops prior to proceeding with the production of the welt.

Viewing the invention from another aspect same resides in effecting the release or press-ofi of the loops to be taken by the welt hooks, by the co-operation with selected needles (alternate needles) of points or equivalent elements which are projected down to take the loops from the nee- .dles while said needles are being lowered and while the welt hooks are retained above the needles.

The invention also includes welting mechanism of the kind referred to, having means independent of the welt hooks for preventing the thread of the first welt course from being engaged in the beards of spaced needles with which the welt hooks co-operate, said thread being engaged in the hooks of the intervening needles.

In order that the invention may be better understood, reference will now be made to the accompanying drawings, in which Figure 1 is a sectional elevation showing, the relevant parts of the welting mechanism, and the needles and sinkers; Figures 2-7 show various stages in the operation of said mechanism;

Figure 8 is a scrap section and Figure 9 a plan, partly broken away, of a presser arrangement that may be employed;

Figure 10 illustrates the use of pressing instructions mounted above the needle row; while Figures 11 and 12 illustrate two alternative arrangements of needle bars.

Referring now particularly to Figs. 1-7, the welt transfer mechanism, which is driven in coordination with the needle movements, is mounted above the knitting mechanism of the machine and above the customary narrowing mechanism (indicated at I24). The said welt mechanism comprises welt bars l0 (one for each division) each carried by and extending between the lower ends of a pair of depending arms II, and each bar being provided with the requisite number of downwardly projecting welt hooks l2, one hook for every other frame needle. The depending arms ll carrying the welt bars have associated therewith at their upper ends link or lever mechanism with cam trucks or rollers coacting with the'peripheral faces of cams (indicated generally at l3 and I4) mounted on a cam shaft I5, rotation being imparted to said cam shaft (5 at the required times from the main shaft l6 of the machine or other suitable working shaft through the intermediary of a clutch or the like (not shown). The cams l4 function to impart vertical movement to the welt bars I0 through the medium of swinging arms ll (from which the arms ll hang at l9) and trucks l8 and the cams I3 function to impart backward and forward movement'thereto. For this purpose spring-biased levers 20, attached to the arms II, project rearwardly from the pivot l9 whereby said arms II are pivoted to the swinging arms l1, and said levers 20 are provided with trucks 2|. The welt hooks l2 are, at the required time, lowered to receive from alternate ones of the frame needles 22 loops appertaining to the first welt course, and then raised sufliciently to hold said loops while the welt is knitted. During the knitting of the welt the cams 13 are rotated so as to permit the springs to rock the dependingarms II to carry the weltbars l0 outwardly in front of the needles to a predetermined distance and back again, and while this is being accomplished the usual welt rods are inserted in the known manner and are connected up to the fabric take-up. After the welt is knitted the welt hooks are caused to assume a position over the needles so that the alternate needles from which the loops were previously released are caused, .on their upward movement, to pierce the loops of the first welt course carried by the hooks said hooks having imparted thereto a vertical motion so as to transfer the loops therefrom tothe' needles. Particularly during the reception from, and the restoration to, the needles, of the loops of the first welt course the welt bars ID are guided against undesirable endwise movement by guides 23.

The mechanism as so far described is substantially similar to that described in British patent specification No. 476,045, to which reference may be made for further details thereof. It may here be emphasized, however, that according to the present invention the mechanism is operated,

during the actual receptiton of the loops, in a manner different to that described in the aforesaid patent specification. According to the said specification, the welt hooks are first lowered at the bearded side of the needles to press alternate frame needles and to receive the loops therefrom. In the exercise of the present invention the welt hooks are not employed to press the needles and hence are not first inserted at the beard side of said needles; on the contrary of spaced (e. g. alternate) needles when the needle bar 24 is lowered. Therefore the loops on said needles are pressed off, that is tosay said loop are prevented from entering or passing under the beards but are caused, on the downward movement of the needles, to be cast off prior to being taken up by the welt hooks I2, the cast off loops being picked up by said welt hooks from the knocking-over bits 25 .by which the cast off loops are received. One method in accordance with this invention of releasing the loops from the frame needles is by projecting Y at the required time between the front face of the presser bar 26 and the alternate needles, presser elements 21 (Fig. 2) which function to press the needle beards and maintain same pressed during the downward movement of the needles for a sufficient time to permit of the loops being passed over the beards, after which 'said presser elements are withdrawn.

Thus the stage shown in Fig. 3 is reached, the loops having been pressed off from, say, every odd needle so that each pressed-off loop extends between a pair of unpressed even needles over a pair of knocking-over bits 25, so that the welthooks 12 may readily be lowered behind the odd needles to transfix said loops. In Fig. 4 a welt hook is shown just entering such a loop, while in Fig. 5 the hook is shown as having completely transfixed the loop.- As will readily be under-. stood, if the hook is now raised, the loop is passed down into the bight of it, where it is securely retained. Thereafter the knitting of the welt proceeds, the welt hooks being gradually moved away from the needles, as shown in Fig. 6, to take up the fabric produced. At a certain stage a welt-rod is inserted and connected to the customary draw-off straps and rollers (not shown). At the completion of thewelt the welt rod is removed, and rotation of the cam shaft l5 brings the welt hooks to the position shown in Fig. '7 (which figure shows one of the needles which was pressed oil. at the commencement of the welt, (e. g. an odd needle) in which they are slightly above and slightly to the front side of the needles. The needles now rise, to transfix the loops held on the welt-hooks, and in their upward movement the beard of each needle moves up the groove in the face of the short limb of the associated welt-hook. During the last part of the upward movement of the needles 4 Thereafter .rotation of cam-shaft I5 ceases .and

the whole welting mechanism may be swung upwards to an inoperative position.

These presser elements operating at alternate individual needles are carried by a suitable bar to which the requisite motion is imparted from any suitable source, conveniently from the main cam shaft of the machine, or from the shaft or other member which controls or imparts automatic movements in the machine;

In the construction illustrated in Fig. "1, the presser elements 21 are carried by a bar 28 arranged to be raised and lowered by levers 29 and 30, rocking about pivot 34, and a truck 3| 00- operating with a cam 32 on-the main cam-shaft I 6. This truck 3| is shiftable by means indicated at 33 (and conveniently controlled from the main chain of the machine or from any suitable control device) to bring it, at the appropriate times, into register either with the cam 32 or with a plain, circular, disc alongside it, it being understood that when the truck engages the disc the bar 28 is not moved.

As the bar 28 is raised the presser elements 21 are advanced towards the needles 22 by means of parts I34 on the machine frame cooperating with inclined faces 35 on the arms 36 by which said bar is connected to the levers 29.

The presser elements may be resilient, and means may be provided for deflecting them towards the needles as said elements are moved in the direction of their length (e. g. as they are raised). In an alternative arrangement (Figs. 8 and 9) the pressing of the alternate needles for releasing the loops therefrom may be effected by providing presser elements 31 on the front face of the presser bar 26 and imparting to said elements a horizontal reciprocating movement to and from the needles (by means not shown, but readily understood by one skilled in the art); while in a further arangement depending presser elements may be carried by a bar located above the needles so as to effect the pressing of the beards by a simple vertical motion.

Thus as shown in Fig. 10, depending points 21 carried by a point bar located above the needles like a picot bar, and appertaining to alternate needles may be operated to descendat the bearded side of said alternate needles, press the beards thereof, receive the loops from said needles and subsequently release said loops on to the knockingover bits, the loops thus released being subsequently picked up by the welt hooks.

In a still further alternative arrangement the frame needles of the machine may be so mounted that alternate needles can be projected to a greater height than the remaining alternate needles, in which case the customary needle presser may at the required time function to press alternate needles for releasing therefrom the loops to be suspended upon the welthooks.

In a further arrangement, Fig. 11, the thread for the first welt course is laid on the shanks of alternate needles only. For this purpose alternate needles are mounted in two needle bars 24 and 24 so that by moving the bar 24 every second needle may be moved to an inoperative position. For example the two bars may be pivoted at 38, so that one set of needles may be swung away from the other set. Alternatively, as shown in Fig. 12 one of the bars 24a or 24b, may be raised and lowered in relation to the other bar so that, at the time when the thread of the initial welt course is laid, the needles thereof are located below the feed level. In such an arrangement it is obvious that thread will only be taken by, say, the even needles at the first course, and after these needles have moved down to take the thread in their beards, the thread portions extending between said needles arepicked up by the welt hooks from the knocking-over bits. At the next thread feed all the needles are brought to the same level so, that all take thread, all of the needles continuing to operate throughout the welt; and on completing the welt, loops held by the hooks are transferred to the aforesaid odd needles.

It may be found unnecessary to displace alterhate needles (odd needles) completely below the thread feeding level, but in any case the extent of It is to be understoood that the invention is not limited to the particular methods hereinbefore described of releasing stitch loops from the frame needles at the first welt course, as other means independent of the welt hooks may be employed for accomplishing this.

I claim:-

1. In welting mechanism of the kind having welt hooks operable from above the needles to receive loops therefrom and subsequently, after the formation of the welt to place said loops on the needles, said welt hooks being provided on a welt bar carried by depending arms guided against undesirable lateral movements, and a cam shaft for operating the welt bar located above the needles; means, independent of the welt hooks, for preventing the thread of the initial welt course from being engaged in the hooks of spaced needles, for reception by the welt hooks, said thread being engaged in the hooks of intervening needles.

2. In welting mechanism of the kind having welt hooks operable from above the needles to receive loops therefrom and subsequently, after the formation of the welt to place said loops on the needles, said welt hooks being provided on a welt bar carried by depending arms guided against undesirable lateral movements, and a cam shaft for operating the welt bar located above the needles; means, independent of the welt hooks, for releasing from the needles the loops that are to be received by said hooks.

3. Mechanism according to claim 2, wherein said independent means comprises presser elements for pressing of the loops.

4. In welting mechanism of the kind having welt hooks operable from above the needles to receive thread kinks of the initial welt course and subsequently to place said kinks on the needles after the formation of the requisite-welt courses, which welt hooks are mounted on a welt bar carried by depending arms and guided against undesired lateral movement, and a cam located above the needles for operating the welt bar; the combination of means, independent of said hooks, for preventing the receptionin the hooks of spaced needles of the thread of theinitial course, and means for inserting the welt hooks at the plain side of the needles to receive the thread kinks extending between the intervening needles;

'5. In welting mechanism of the kind having welt hooks operable from above the needles to receive thread kinks of the initial welt course and subsequently to place said kinks on the needles after the formation of the requisite welt courses, which welt hooks are mounted on a welt bar carried by depending arms and guided against undesired lateral movement, and a cam located above the needles for operating the welt bar; the combination of knocking over bits, presser means independent of the welt hooks for pressing off spaced kinks onto said bits, and

means for inserting the welt hooks at the plain side of the needles to receive said pressed-off kinks.

6. Mechanism according toclaim 2, wherein 7 said independent means comprises presser instruments, and a bar below the needles on which said instruments are mounted.

7. Mechanism according to claim 2, wherein the said independent means comprises a presser bar for pressing oil the loops from spaced needles.

8. In a straight bar knitting machine havin a line of bearded needles and thread-laying means, said needles being movable in the direction of their length to knit, welting mechanism comprising a welt bar, welt hooks thereon for spaced needles, depending arms carrying said bar, a support for said arms, means independent of said welt hooks for causing said spaced needies to miss the thread of an initial welt course upon descent of the needles, and means, including cam mechanism mounted above the needles, for inserting the welt hooks at the plain side of said spaced needles to receive the thread portions missed thereby and, after the formation of the requisite number of welt courses, to restore said thread portions to the spaced needles.

9. In the combination according to claim 8, means, included in said cam mechanism, for pcsitioning the welt hooks at the hook side of the needles to restore the thread portions thereto.

10. In a knitting machine, mechanism according to claim 1, and means for moving spaced needles to a position wherein they do not receive the thread of an initial welt course, said thread being received on intervening needles.

11. Mechanism according to claim 2, wherein said independent means comprises presser instruments for pressing oi! thread of the initial course from spaced needles and for receiving the pressed-oi! thread.

12. In a straight bar knitting machine having a line of bearded needles and thread-laying means, said needles being movable in the direction of their length to knit, welting mechanism comprising a welt bar, welt hooks thereon. for spaced needles, depending arms carrying said bar,

a support for said arms, knocking over bits, pressers extending up between the said bits, a

mounting for said pressers below said bits, means for operating said pressers to press spaced needles to cast of! spaced kinks of an initial welt course, and means, including cam mechanism mounted above the needles, for inserting the welt hooks at the plain side of said spaced needles to receive the thread portions missed thereby and, after the formation, of the requisite number of welt courses, to restore said thread portions to the spaced needles.

13. A method of producing a turn-over welt on a knitting machine, having hooked needles and means for preventing the reception of portions of an initial welt course in the hooks of spaced needles, by the employment of welting mechanism of the kind having welt hooks operable from above the needles to receive thread portions of said initial course and subsequently toofler said loops to the needles, said welt hooks being provided on a welt bar carried by depending arms and guided into register with the needles, cam mechanism located above the needles for operating the welt hooks, which method comprises lowering the welt hooks at the plain side'of said spaced needles to receive said thread portions, and subsequently locating the hooks at the hooked side of the needles to ofler said thread portions to the needles.

14. A method of producing a turn-over welt,

on a. knitting machine having bearded needles, by the employment of welting mechanism of the kind comprising a support, arms depending therefrom, a welt bar carried by said arms, welt hooks for spaced needles carried by said bar, means for restraining endwise movement of said bar, and cam mechanism located above the needles for operating the hooks to receive thread portions of an initial welt course extending across said spaced needles and subsequently to ofler said portions to said needles, which method com-- prises the step of preventing, by the use of means independent 0! the welt hooks, the thread of said initial course from being engaged in the beards 0! said spaced needles.

LEWIS HENRY COL-TON.

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