US2984092A

US2984092A - Straight bar knitting machines

Info

Publication number: US2984092A
Application number: US700673A
Authority: US
Inventors: Start Ernest
Original assignee: William Cotton Ltd
Current assignee: William Cotton Ltd
Priority date: 1956-12-14
Filing date: 1957-12-04
Publication date: 1961-05-16
Anticipated expiration: 1978-05-16

Description

May 16, 1961 E. START 2,984,092 STRAIGHT BAR KNITTING MACHINES Filed Dec. 4, 1957 5 Sheets-Sheet 1 ii-M f-flukba.

Attorney E. START 2,984,092 STRAIGHT BAR KNITTING MACHINES F iled Dec. 4, 1957 3 Sheets-Sheet 2 Attorney May 16, 1961 E. START 2,984,092

STRAIGHT BAR KNITTING MACHINES Filed Dec. 4, 1957 3 Sheets-Sheet 3 [n venlor ag-(4w .wa

A ttorn e y United States Patent STRAIGHT BAR KNITTING MACHINES Ernest Start, Wilford, Nottingham, England, assignor to William Cotton Limited This iI 1vention relates to improvement in straight bar rib knitting machines and is concerned primarily with press-offs. When a press-off has occurred in such machines and it is attempted to resume knitting, the absence of adequate tension on the newly formed loops causes the knocked-over machine needle loops to remain at such a high level as to become again positioned machine needles when next advanced. If this is continued for a number of courses, a ravelled band of yarn is built up WhlCh is repeatedly penetrated by the machine needles while no properly knitted fabric is produced.

When it is required to start knitting an article it has heretofore been necessary to first run-on a short length of fabric to enable at the beginning of the knitting operatron the production of a properly knitted fabric.

An object of the invention is to provide means enabling the machine to automatically resume the producnon of properly knitted fabric after a press-off, and another object is to enable the machine to start a properly knitted fabric without the aid of run-onfabric.

With this object in view, the present invention relates to a straight bar knitting machine for making rib fabric, and comprises a set of first needles and a set of second needles, and a slide bar having a bottom surface, a top surface formed with upper trick slots have upper trick bases and receiving said first needles for sliding movement, and a front surface formed with lower trick slots extending to the bottom surface as continuati'ons of the upper trick slots, and having lower trick bases extending transverse to the respective upper trick bases.

When the first needles draw new loops through the respective old loops, the front surface engages the old loops while the new loops are drawn by the first needles into the lower trick slots. Consequently, the old loops are deflected by the front surface, which is preferably downwardly inclined toward the bottom surface, and assume a position located below the level of the upper trick bases at which the needles are located permitting the needles to advance without penetrating the old loops.

Preferably, the lower trick slots in the front surface of the slide bar are substantially wider than the first needles corresponding to the width of the new loops held by the needles. The upper trick slots, except for guide grooves for the first needles, are also much wider than the thickness of the needles.

The front surface of the slide bar preferably merges into the bottom surface along a curved surface portion, and is undercut in the region of the top surface.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself will be best understood from the following description of a specific embodiment when read in connection with the accompanying drawing, in which:

Figures 1 to 9 are diagrammatic illustrations of the steps of forming loops in a straight bar rib knitting machine according to the invention. Fig. 1 shows a yarn feeding step, Fig. 2 shows a yarn sinking or measuring step, Fig. 3 shows a needle-beard pressing step, Fig. 4 shows the drawing of the yarn to the sinker nibs, Fig.v 5 shows the knock-over position, Fig. 6 shows a second needle-beard pressing step, Fig. 7 shows the needles moving back towards a knock-over position, Fig. 8 shows a second knock-over position, and Fig. 9 shows the advancement of the needles after the second knock-over step.

Figure 10 is a diagrammatic perspective view of the stepshown in Figure 8.

Figure 11 is a cross sectional view of a tricked slide bar according to the'invention,

Figure 12 is an end view of part of this Figure 11 looking in the direction of the arrow 12-.

Figure 13 is a sectional view of part of this Figure 11 on line 1313.

Referring now to the drawings the straight bar rib knitting machine of the invention is represented by frame needles 1, sinkers 2, a thread carrier 3, knocking over bits '4, machine needles 5 and a tricked slide bar 6 in which the machine needles 5 operate.

As best seen-in Figs. 8 and 10 to 13, the slide bar 6 has a top surface, a bottom surface 6c, and a front surface 6a. The top surface is formed with upper trick slots 6d having upper trick bases 6e, and the front surface 6a is formed with lower trick slots forming continuations of the respective upper trick slots'6d and having trick bases 6f which extend transversely to the upper trick bases 6e. Trick walls are thus formed between adjacent trick slots, and the front surface 6a is consequently formed by the front faces of the trick walls which merge into the bottorn surface 6c at edges 6b, as shown in Fig. 11, or merge into the bottom surface along a curved surface portion 6b as shown in Figs. 1 to 9.

Referring now to Figure l, in the illustrated position, the old loops liiL hang on the frame needles 1 and the old loops 50L hang on the machine needles '5, with the sinkers .2 partly withdrawn and the thread carrier 3 feeding a new yarn NY to the sinker nibs.

Figure 2 shows the position in which the new yarn NY has been placed by the sinkers 2 between the frame needles 1 which are operated for knitting before the machine needles 5 knit.

Figure 3 shows the pressing position of the frame needles 1 wherein these needles press their beards 1a against the presser edge '7 after the loops of new yarn NY on these needles have been received in their beards and before the old loops 101. on the needles are about to be landed onto the beards.

Figure 4 shows the sinkers 2 retracted to allow the loops of new yarn NY to ride to the ends of the sinker nibs, with the old loops IOL on the beards of the frame needles 1.

Figure 5 shows the knock-over in position which the sinkers 2 are fully retracted and the frame needles 1 move towards the machine slide bar 6 so that the loops of new yarn NY drop off the sinker nibs and, by a knocking-over motion of the frame needles 1 and knockingover bits 4, said loops of new yarn NY in the beards of frame needles are drawn through the old loops 16L by the frame needles 1 to form new frame needle loops lNL. It will be observed from Figure 5 that the motion of the frame needles 1 carries those remaining loops of new yarn NY and the old loops 50L which are on the machine needles 5 to a location on the shanks of the machine needles 5 adjacent the tips of the machine needle beards 5a. 7

Figure 6 shows the machine needles 5 advancing to knit these loops. The machine needles are first advanced until their beards 5a are pressed against the bottom face of presser edge 8 and enclose the loops of the new yarn NY which was carried by the frame needles 1 under the beards a. Thereupon, the machine needles 5 are moved to land the old loops on their beards 5a, which are held closed by presser edge 8.

Figure 7 shows the machine needles 5 partly retracted towards knock-over position, with the old loops 50L landed on the machine needle beards 5a in engagement with the inclined edge 6a of the machine slide bar 6. The knocking-over bits 4 are also advanced.

Figure 8 shows the knock-over position of the machine needles 5 in which their beards have been withdrawn into the upper tricks 6d of the machine slide bar 6. As a result of this the old loops 50L are cast-off the ends of the machine needle beards 5a over the loops of yarn NY to form new machine needle loops 5NL. In this motion these newly drawn loops SNL are drawn into the lower trick slots 6) in the front surface 6a of the bar 6 by the machine needles 5 as allowed by the extra width of trick slots 6 which exceeds the thickness of needles 5. The knocked-over old machine needle loops 50L are engaged, cammed down, and deflected by the front surface 6a of the trick walls and pass over the rounded surface portion 6b, as best seen in Figs. 8 to 10. The knocking-over bits 4 may be further slightly advanced to assist this knocking-over, if desired.

The step of Figure 8 is also illustrated in diagrammatic perspective view in Figure 10 and, as clearly shown in Figures 8 and 10, the camming down of the newly knocked-over loops 50L by the rounded edge 6b of the slide bar 6 carried out to such an extent that these loops 50L are below the level of the trick bases 62, 6g and removed from the path of movement of the machine needles 5 when the latter advance again as shown in Figure 9.

It will be understood from the above description that by the employment of the slide bar 6 with its deflecting front surface 6a and 6b it is possible to resume knitting of a properly knitted fabric after a press-ofl'; similarly it is possible to commence knitting of an article without the aid of a run-on piece of fabric.

I claim:

1. In a straight bar rib knitting machine for the pro duction of rib fabric, the combination of two sets of associated needles for forming loops, a horizontol type slide bar having upper tricks with bases in which the needles of one of said sets of needles are slidable to draw new loops taken from the other set of needles through old loops suspended from the needles of said one set and to cast-off said old loops, and said slide bar having a yarndeflecting surface spaced forwardly and downwardly of said bases of said upper tricks in a manner for positively engaging and deflecting said cast-off old loops below their associated needles and ensure against penetration of these loops by these needles whereby said fabric can be knitted following a press-01f and for starting up without run-on fabric, said slide bar having a forward undercut edge and a bottom surface spaced well below said bases of said upper tricks, and an angular formation between said forward undercut edge and said bottom surface, said angular formation being rounded to have the required positively engaging and deflecting action on said cast-off loops.

2. In a straight bar knitting machine, in combination, a set of first needles and a set of second needles for forming loops; and a slide bar having a bottom surface, a top surface formed with upper trick slots having upper trick bases and receiving said first needles for sliding movement, and a front surface formed with lower trick slots extending to said bottom surface as continuations of said upper trick slots, respectively, and having lower trick bases extending transverse to the respective upper trick bases, said front surface engaging and retaining old loops on said first needles while new loops taken from said second needles are drawn by said first needles into said lower trick slots whereby said old loops are cast off and deflected by said front surface below the level'of said upper trick bases permitting said first needles to advance at the level of said upper trick bases without penetrating the old loops.

3. In a straight bar knitting machine, in combination, a set of first horizontal needles and a set of second vertical needles for forming loops; and a slide bar having a bottom surface, a top surface formed with upper trick slots having upper trick bases and receiving said first horizontal needles for sliding movement, and a front surface formed with lower trick slots extending to said bottom surface as continuations of said upper trick slots, respectively, and having vertical lower trick bases, said front surface engaging and retaining old loops on said first needles while new loops taken from said second needles are drawn by said first horizontal needles into said lower trick slots whereby' said old loops are cast off and dcflected by said front surface below the level of said upper horizontal trick bases permitting said first horizontal needles to advance at the level of said upper horizontal trick bases without penetrating the old loops.

4. In a straight bar knitting machine, in combination a set of first needles and a set of second needles for forming loops; and a slide bar having a bottom surface, a top surface formed with upper trick slots having upper trick bases and receiving said first needles for sliding movement, and a front surface formed with lower trick slots extending to said bottom surface as continuations of said upper trick slots, respectively, and having lower trick bases extending transverse to the respective upare cast off and deflected by said downwardly inclined front surface below the level of said upper trick bases permitting said first needles to advance at the level of said upper trick bases without penetrating the old loops.

5. An arrangement as set forth in claim 4 wherein said lower trick slots and said lower trick bases are substantially wider than said first needles corresponding to the width of said new loops held by said first needles.

6. An arrangement as set forth in claim 4 wherein said upper trick slots are substantially wider than said first needles, and wherein said upper trick bases have centrally located guide slots matching the thickness of said first needles and slidably receiving the same.

7. In a straight bar knitting machine, in combination, a set of first needles and a set of second needles for forming loops; and a slide bar having a bottom surface, a top surface formed with upper trick slots having upper trick bases and receiving said first needles for sliding movement, and a front surface extending between said top surface and said bottom surface and being formed with lower trick slots extending to said bottom surface as continuations of said upper trick slots, respectively, and having lower trick bases extending transverse to the respective. upper trick bases between said upper trick bases and said bottom surface, said front surface being downwardly inclined from said top surface toward said bottom surface and engaging and retaining old loops on said first needles while new loops taken from said second needles are drawn by said first needles into said lower trick slots whereby said old loops are cast off and deflected by said downwardly inclined front surface below the level of said upper trick bases permitting said first needles to advance at the level of said upper trick bases without penetrating the old loops.

8. In a straight bar knitting machine, in combination, a set of first needles and a set of second needles for forming loops; and a slide bar having a bottom surface, a top surface formed with upper trick slots having upper trick bases and receiving said first needles for sliding movement, and a front surface extending between said top surfaceand said bottom surface and being formed with lower trick slots extending to said bottom surface as continuations of said upper trick slots, respectively,

bottom surface along a curved surface portion and being 0 undercut in the region of said top surface whereby said old loops are cast off and deflected by said downwardly inclined front surface below the level of said upper trick bases permitting said first needles to advance at the level of said upper trick bases without penetrating the old loops.

References Cited in the file of this patent UNITED STATES PATENTS 621,723 Lowe Mar. 21, 1899 654,982 Hurley et a1. July 3, 1900 FOREIGN PATENTS 72,035 Austria Sept. 15, 1915 341,094 France June 1, 1904 674,930 Germany Apr. 6, 1939