US2127537A - Needle bed for knitting machines - Google Patents

Description

3,1938. CSCHURICHTI 2,127,537

NEEDLE BED FOR KNITTING MACHINES Filed April 11, 1936 2 Shets-Sheet l 2/ I 22 20 v l N l\ w 'I A INVENTOR Carl Schurichf ATTORNEY A gc. scHumcHT 2,127,537

NEEDLE BED FOR KNITTING MACHINES Filed April 11, 1936 2 Sheets-Sheet 2 Fig.9

INVENTOR gYarl Schur-ichf ATTO R N EY Patented Aug. 23, 1938 NEEDLE BED 'FOR KNITTING MACHINES Carl Schuricht, Hollis, N. Y., assignor to Max B.

. Nydegger, Summit, N. J.

Application April 11.

8 Claims.

The present invention relates to knitting machines generally and more particularly the invention relates to such machines of the type comprising at least two needle beds mounted in ad- I -.'|acent positions with an open passage for the yarn and fabric therebetween.

The usual type of needle bed now in use in the flat bed type of knitting machine consists of an elongated, rectangular metal plate having a plurality of grooves milledtherein which support the needles and the needle jacks and guide the movements of these elements duringthe operation of the machine.

The grooves in the needle bed are at right angles to the longer sides of the needle bed and extend thereacross. Hereinafter the long side of the needle bed adjacent the corresponding side of the other needle bed will be termed the work side since that is the side whereat the work, that ao'is, the knitting of the yarn, takes place The bottom of each groove is a plane and the maximum depth of the groove is at each end thereof. A short distance back from the work side of the needle bed the sides of the grooves are reduced to 25 their minimum depth and the depth thereof increases in a series of steps as the distance from the work side increases. At an appreciable distance from the work side of the needle bed the grooves are again at their maximum depth to guide the needle jacks. One end of each side of each groove is contiguous with the work side of the bed and serves as an immovable post around which the yarn is pulled into the groove by the needle during the operation of the knitting machine. This post is known in the art as a tooth and will be identified hereinafter. by that term. The grooves are at their maximum width at the work side of the bed and the width thereof is reduced to slightly more than the width of the needle jack at the end of the minimum depth part of the groove.

There are many disadvantages connected with the type of needle bed described above and which are at present in extensive use in the art. From the standpoint of manufacture of the needle bed the material from which the entire bed is made is controlled by the material best suited for the teeth. Inasmuch as the teeth are apt to be struck with considerable force and bent when a needle is accidentally lifted up from the bottom of the groove andhit by the needle actuating means traveling over the needle bed a ductile material is best suited for the teeth since the teeth can be forced back into position after being bent.

This type of material does not lend itself;"

1936, Serial No. 73,895

as readily to the milling of the grooves as does a harder material. Another disadvantage of making the teeth integral with the needle bed is that the finishing and polishing of the surfaces of the teeth and the grooves across which the yarn is pulled is a dlfl'lcult and expensive hand operation due to the narrow width ofthe grooves and is one inwhich the highest degree of skill produces inaccurate and imperfect results. The importance of having smooth surfaces of the same geometric configuration on the teeth and the other parts of the needle bedacross which 'the yarn is pulled during the operation of the machine is apparent when it is realized that the yarn worked upon by the machine consists of a large number of twisted fibers, frequently has a rough surface and frequently does not have a large tensile strength. Further, when knitting certain types of stitches the yarn is pulled back and forth over as many as four teeth and into three grooves. Obviously under these conditions the surfaces of the teeth and the-other parts of the needle bed in contact with the yarn must be as smooth as possible to avoid catching the fibers of the yarn and of such configuration that it offers a minimum resistance to the travel of the yarn thereacross. As pointed out above the formation of these surfaces of the needle bed and the polishing thereof by hand is a difficult and expensive operation and imperfect results are obtained.

While it has not' been emphasized above there is considerable wear on the teeth and the other surfaces of the needle bed across which the yarn is pulled during the operation of the machine and while there are many materials more resistant to this wear than a ductile material the necessity for ductility in the teeth has dictated the choice of the material used for the parts of the needle bed in contact with the yarn.

From the foregoing it isbelieved to be apparent that the needle beds now in use in the art represent a compromise and that the, materials best suited forthe various parts of the needle bed, both from amanufacturing standpoint and from the standpoint of the use made of the parts in the operation of the knitting machine, have not been employed heretofore.

The object of the present invention is to provide a needle bed for a knitting machine which is inexpensive to manufacture, is easily repaired, and which has a long useful life. Another object of the invention is to provide a needle bed like parts of which have the same geometric configurationand a configuration best suited for its purpose. Still another object of the invention is to provide a needle bed the various parts of which are in such relation to each other that the operation of racking the knitting machine, by which is meant the longitudinal displacement of one needle bed with respect to the other, is facilitated. A further object of the invention is to provide a needle bed of such structure that .many types of stitches impossible of formation on machines comprising needle beds of the prior art are successfully knitted. A still further object of the invention is to provide a needle bed of such structure that many types of yarns, filaments, or ribbons heretofore useless in connection with knitting machines are successfully knitted by such machines. Still further objects and advantages attaching to the device and to its use and operation will be apparent to those skilled in the art from the following particular description.

The invention attains its objects by making the teeth separable from the needle bed and by providing removable means on the needle bed to rigidly support the teeth in their proper position on said bed. The teeth are easily inserted into and removed from said supporting means. The teeth and the needle bed can thus be manufactured separately and be made of different materials better suited to the manufacturing processes and the use to which each of these elements are subjected. For example, the part of the needle bed in which the grooves for the needle jacks are milled can be made of a harder material better suitedto milling than was the practice heretofore when the teeth were made integral with the other parts of the needle bed. The teeth can be made and polished by mass production methods in a uniform, perfect shape more suitable for its purpose than was possible by the manual methods inuse prior to the present invention. The smooth, perfectly formed surface of the machine made teeth offers a minimum of resistance.

to the yarn and obviates catching of the fibers which makes possible the successful knitting of a large number of rough, large fibered yarns and yarns, filaments, or ribbons of low tensile strength or limited flexibility and elasticity which could not be successfully worked upon by knitting machines having needle beds in which the teeth were made integral with the other parts thereof due to the comparatively rough and imperfectly shaped teeth of such prior needle beds.

Another advantage of the needle bed made in accordance with the present invention is the ease and celerity with which damaged teeth may be repaired or replaced. When the teeth are accidentally bent in needle beds having the teeth integral therewith it has beenthe practice to bend the teeth back into shape. The ductility of the teeth made such bending possible. The bending of the teeth and the impact of the needles on the teethleft a rough surface which had to be carefully smoothed down by hand in order to avoid catching of the yarn. This polishing operation was imperfect at best and took considerable time, the machine standing. idle while this operation was performed. Further, after the teeth had been bent and repaired a number of times they were considerably weakened and broke off at the joint therebetween which would catch the yarn and break it. This takes considerable time, requires highly skilled labor and frequently necessitates the removal of the needle bed from the machine. When the tooth is made separable from the needle bed, in accordance with the present invention, a damaged tooth is easily removed from the needle bed, a perfect tooth is inserted in its proper position therein'without disturbing any of the other parts of the machine and the machine is again ready for use. This operation requires little mechanical skill and can be performed by the operator of the knitting machine.

The invention will be readily understood from an inspection of the drawings accompanying and forming part of this specification and from a pcrusal of the following detailed description thereof.

' strip useful in the embodiment ofthe invention illustrated in Figs. 2 and 3, showing the teeth in position therein,

Fig. 5 is a. perspective view ofthe preferred form of tooth useful in the embodiment of the invention illustrated in Figs. 2 to 5,

Fig. 6 is a fragmentary end view of the preferred embodiment of the invention,

Fig. 7 is a fragmentary top view of the embodiment of the invention illustrated in Fig. 6,

Fig. 8 is a side elevational -view of the preferred form of tooth useful in"the embodiment of the invention shown in Figs. 6' and 7, and

Fig. 9 is a top view of the tooth shown in Fig. 8. Like numbers denote like parts in all the figures. Referring to Fig. 1 of the drawings each of the needle beds l illustrated consists of an elongated, rectangular plate having a plurality of grooves or slots extending across the width thereof which guide the movements of the needle 20 and the 'needle jack 2| which connects the needle 20 with the actuating means during the operation of the machine. The slots in the needle beds are in alignment so that the needles 20 can slide from one needle bed to the other in forming certain stitches. It will be noted that the teeth 22 are integral with the slotted. part of the needle beds I. The disadvantages of such structure, both from a manufacturing standpoint and in the use of the machine, have been pointed out above. It

will be noted further that the slot terminates in a plane passing through the work face of the tooth. The disadvantages of this structure will be pointed out below.

In the embodiment of the invention illustrated in Figures 2 to 5 of the drawings the needle bed I consists of an elongated, rectangular metal plate I having a plurality of slots 2 milled therein in the manner now known in the art. The

height of the ridges 3 separating the slots diminishes in a series of steps from the back face to the forward work face of the bed I, as shown in Fig. 2. The lowest step, H which terminates at the work face of the needle bed I, is thinner than the other steps, as shown in Fig. 3, and is just sumcient in height to guide the needle an the yarn in their movements therein.

The underside of the work face of the needle bed I is cutout in the form of a rabbet (Fig. 2)

(Fig. .4). The holding strip 4 is fastened to the needle bed I by a'plurality of threaded bolts 1 which are inserted in the counter-sunk holes 8 of the holding strip 4 and screwed into threaded holes in'the underside of the needle bed I. The holes 8 and the threaded holesin the needle bed are in such position that the grooves are directly underneath the ridges 3. so that the vertical part II of each tooth 6 is in line with one of the ridges 3 when. these elements are assembled to form a unit. The height of the part 9 of each of the teeth 6 in the slots"5 ,of the holding strip 4 is equal to the depth of said slots 5 and extends a considerable distance along said slot 5 so that when the holding strip 4 is fastened to the needle bed I the tooth 6 is rigidly held in its proper in Fig. 5 of the drawings. The'metalused for the tooth 6 is a harder and more resilient one.

than is practical to use for this part in the type of needle bed illustrated in Fig. lgwhich must be of a ductile metal. The harder material of the teeth 6 makes possible the knitting of many materials, such as metal filaments, which could .not

the tooth 6 a blank is first stamped out which 'is' then bent or folded back on itself to form the tooth 6 illustrated in Fig. 5 which is smoothed and polished after the bending operation. The: folding of the blank forms a rounded front face on the upper part II of the tooth 6 is smooth and is contiguous with the work face of the grooved por- 'tion I of the needle bed to avoid an opening between these surfaces which would catch the fibers of the yarn. The back portion of lower part 9 of the tooth 6 is flared in a V shape so that when the said part 9 is inserted in the grooves 5 of the holding strip'4 the sides thereof press tightlyagainst the sides of the grooves 5 to resist any force tendingto pull said tooth" 6 outof the groove 5.

In the event that any of the teeth 6 are bent out of shape or broken during the operation of the machine the removal thereof from the needle bed and the replacement thereof with another perfect tooth is accomplished "by removing the holding strip 4 from the needle bed, which is accomplished without disturbing any of the other parts of the knitting machine, extracting the damaged tooth or teeth from the grooves 5, inserting a perfect tooth in the grooves 5, and replacing the holding strip 4 on the needle-bed I. This repair of the machine can be done by the operatorthereof since it requires mechanical skill well within that possessed by the average operator of knitting machines and is accomplished in ash'ortftime.

The preferred embodiment. of the invention is illustrated in Figs. 6 to 9 of the drawings. In

this embodiment of the invention the slotted part of the needle bed I terminates at the part thereof whereat the ridges begin to decrease in width in the usual type of needle bed to forni the wider part of the slot into which the yarn is pulled by I the needles. The grooved part I5 of the holding strip 4 is of sufficient height that the top surface thereof between the grooves is in the same plane 4 as the bottom of the grooves in the needle bed I and supports the needle and the yarn. The parts 9 of the teeth 6 extend beyond the top surface of the holding strip 4 to form the sides of grooves. The back surface of the slotted part of the holding strip 4 is separated from the adjacent surface of the needle bed I a distance sufficient to permit the insertion of the flared parts III of the teeth 6 therebetween, as shown in Figs. 7 and 8.

In this embodiment of the invention the flared parts III of the teeth 6 are greater in height than the 'part 9 thereof in the slots of the holding strip 4, as shown in Figs. 6 and 8, and when the various elements of this embodiment of the invention are assembled the top of the parts III are in the same plane as the top of the contiguous part of the ridge 3 of the needle bed as shown in Fig. 6.

As the needle is moved along the slot 2 of "the knitting machine it is frequently forced against the sides of said slots 2 and the end thereof strikes and rubs against the part of the slot 2 whereat the width of the slot grows smaller.

on the flared part III of the teeth 6 rather than the needle bed itself which prolongs the useful life of the slotted part of the needle bed I. The

bottom parts I6 of the teeth 6 protrude beyond,

the back edge of said teeth 6 and when the holder 4, and the teeth 6 are assembled on the needle bed I the protruding lower part of .the teeth 6 fit into a rabbet in the needle bed I, as shown in Fig. 6. The holding strip 4 is rigidly attached to the needle bed I by the screws I and the teeth 6 are immovably held in position by the-structure described above.

The element I3 of the embodiment of the invention illustrated in Figs. 6 and '7 is a wire which. is drawn through a perforation I2 in each of the teeth 6, which perforations I2 are in alignment when the teeth 6 are mounted in position in the holding strip 4. The diameter of the wire I3 so The wear; incident to this striking and rubbing is exerted closely approaches .that of the perforations I2,

that the surface of the wire is contiguous with that of the perforations I2. Catching of the yarn betweensaid surfaces is thus an impossibility. The wire I3 is slightly below the plane of the upper surfaces of the holding strip 4 and is.

. recessed slightly from the rounded front face of the teeth 6. In this position the wire I3 is sub- .force exerted on the needles-by the weight customarily attached to the knitted fabric is exerted vertically rather than in a direction at an angle to the vertical and toward the opposite needle bed as in the prior types of needle beds in which the work face of the needle bed is in the same plane as the front surface of the teeth. This has been a source of considerable difliculty in knitting machines in the past due to the fact that the lateral &

force exerted on the needles would pull one of the ends thereof out of the groove or slot and beyond the work face of the needle bed. Frequently the needles would be pulled beyond the work face of the needle bed and into the passage between the beds to such an extent that when the needle beds were racked, that is, when one needle bed was moved longitudinally with respect to the other needle bed, the needles in the opposing needle beds would strike each other and would be bent or broken. Attempts to solve this problem have included complicated apparatus to separate the beds before racking and to move and hold the needles in a retracted position in the needle beds before and during the racking operation. When-a vertical pull on the yarn is exerted at a point recessed from the front face of the teeth 6 the necessity for the complicated and expensive mechanisms of the prior art no longer exists since the ends of the needles cannot be moved beyond the front face of the teeth 6 by the vertical pull on the yarn.

When the downward force on the needles is exerted at. a point recessed from the front face of the teeth 6 many novel stitches impossible of formation on knitting machines heretofore without special means are successfully knitted without such means. For example, a half-cardigan stitch in the formation of which the yarn is laid into the hook of the needle without the immediately preceeding stitch being knitted ofi the needle and a third stitch is then knitted into the two previous stitches is successfully knitted on a machine having needle beds embodying the present invention. In the formation of .a stitch of this type the first formed stitches must be held on the needle latch while the second stitch is being formed which is the teeth 8 are made in two parts, when desired,

each of which parts have the same configuration substantially as the teeth shown and described herein and which fit tightly together when inserted in the grooves of the holding strip 4 to form; a single tooth.

I claim as my invention:----

1. A needle bed for a knitting machine comprising a slotted member, a holding strip removably fastened to said slotted member and a plurality of teeth removably mounted in said holding strip, said holding strip having a plurality of grooves therein to accommodate said teeth, each 01' said teeth having a resilient, expanded portion greater in thickness than the width of said grooves for engaging with said strip.

2. A needle bed for a knitting machine comprising a slotted member, a grooved holding strip removably fastened to said slotted member and a plurality of resilient teeth removably mounted in the grooves of said holding strip said teeth being held in said grooves by the friction resulting from the resiliency thereof.

3. A needle bed for a knitting machine comprising a slotted member, a grooved holding strip removably fastened to said slotted member and a plurality of teeth removably mounted in the grooves of said holding strip, the part of said teeth in said grooves being resilient and pressing tightly against the sides of said grooye to hold said teeth in position in said holding strip, another part of said teeth being substantially at right angles to the part thereof in said groove and being in line with the ridges in said slotted member.

4. A needle bed for a knitting machine comprising a rectangular slotted member, a holding strip removably fastened to said slotted member and a plurality of teeth removably mounted in said holding strip, each of said teeth being perforated, the perforations in said teeth being in a line parallel to one side of said slotted member, slightly below the level of the bottom of the slots therein and slightly recessed from the front face of said teeth and a wire extending through said perforations.

5. A needle bed for a knitting machine comprising a slotted member, a grooved holding strip removably fastened to said slotted member and a plurality of teeth removably mounted in the grooves of said holding strip the top surface of said holding strip being in the same plane'as the bottom surface of the slots in the slotted member, the parts of said teeth in, said holding strip extending above the top surface thereof having a flared end equal in height and width to the ridges between .said slots: and being in line with said ridges. 6. A tooth for detachable engagement with the slotted needle bed of a knitting machine, said tooth having two parts substantially at right angles to each other, one of said parts having a resilient expanded portion along its length for engaging with said needle bed.

'7. A tooth for detachable en agement with the slotted needle bed of a knitting machine, said tooth being a folded member having two parts substantially at right angles to each other, one of being perforated to accommodate a yarn guidin no element.

CARL SCHURICI-IT.

Images