US3257828A

US3257828A - Multi-feed knitting machine for reinforcing flexible hose or the like

Info

Publication number: US3257828A
Application number: US312971A
Authority: US
Inventors: Greczin John
Original assignee: Singer Co
Current assignee: Singer Co
Priority date: 1963-10-01
Filing date: 1963-10-01
Publication date: 1966-06-28
Anticipated expiration: 1983-06-28

Description

.1. GRECZIN 3,257,828 MULTI-FEED KNITTING MACHINE FOR REINFORCING June 28, 1966 FLEXIBLE HOSE OR THE LIKE 2 Sheets-Sheet 1 Filed 001,. l, 1965 ATTYS.

June 28, 1966 J. GRECZIN 3,257,328

MULTI-FEED KNITTING MACHINE FOR REINFORCING FLEXIBLE HOSE OR THE LIKE 2 Sheets-Sheet 2 Filed Oct. 1, 1965 FIG-4.

INVENTOR. JOHN GRECZIN Mai 69 ATTYS.

' one relative revolution of the cylinder.

United States Patent "ice 3,257,828 MULTI-FEED KNITTING MACHINE FOR REIN- FORCING FLEXIBLE HOSE OR THE LIKE John Greczin, Philadelphia, Pa., assignor to The Singer Company, New York, N.Y., a corporation of New Jersey Filed Oct. 1, 1963, Ser. No. 312,971 2 Claims. (Cl. 66-38) The present invention relates to circular knitting machines and particularly to circular knitting machines of the type which make a knit tubular fabric for reinforcing flexible hose and the like.- I

In circular knitting machines knitted fabric is formed by yarns cooperating with reciprocating needles mounted about the periphery of a needle cylinder, and the reciprocation of the needles is caused by relative movement or rotation between a cam box and the needles. In the present state of the art of small-cylinder circular knitting machines, it is diflicult and highly impractical to attempt to obtain more'than four courses for every relative revolution between the cam box and the needles. The number of courses that may be produced in a smallcylinder circular knitting machine during one relative revolution, is limited by the means by which the needles are caused to reciprocate to form stitches. The most common means for causing the needles to reciprocate in machines of this variety is a cam track in the cam box in which rides a projection from the needle, commonly called the needle butt, which first raises the needle by engagement of the lower portion of the butt in the cam track and then lowers the needle to draw the stitch by engagement of the upper portion of the needle butt in the cam track. Thus the number of courses of knitted fabric which each needle may knit during one revolution of the cylinder with respect to the cams is determined by the number of times that the needle raises or lowers during any one relative revolution of the cylinder, there being a separate yarn feed adjacent each point where the needle reaches its uppermost position.

It has been found that if the angle which the normal to a cam vtrack makes with the longitudinal axis of a needle exceeds 45 degrees (45), binding of the needle butts, excessive wear, and in many instances Smashups occur. Thus the limitation is imposed that the smaller the diameter of the knitting machines needle cylinder, the fewer the yarn feeds that may be used, and consequently the fewer the number of courses which may be knit in From the foregoing then it is readily understandable that in comparatively large diameter circular knitting machines, the number of feeds, and consequently the number of courses per revolution of the cylinder, may be increased in accordance with this increased circumferential size, because the cam track which the butt of the needle must follow may easily increase the number of reciprocations of the needle without exceeding the 45-degree angle limitation. However, it should be noted that the larger the diameter of the cylinder of the machine the larger the diameter of the material being knit, and in the case of knitting, for example, a reinforcing web for small diameter flexible hose, the use of a large diameter machine is undesirable and impracticable.

In accordance with the present invention, means are provided wherein a plurality of courses may be knit upon one revolution of the cylinder. More specifically, the present invention provides means for circumventing the 45-degree angle limitation thereby permitting an increased number of knitted courses per revolution.

Another object of the present invention is to produce a small diameter tubular fabric much more rapidly than heretofore known in the art on small cylinder knitting machines.

3,257,828 Patented June 28, 1966 Another object of the present invention is to produce a tubular knitted fabric composed of individual mutually overlying knitted webs to provide a smooth front and back face in the fabric and to improve the burst strength of flexible hose or the like.

Other objects and a fuller understanding of the invention may be had by referring to the following description and claims taken in conjunction with the accompanying drawings in which:

FIG. 1 is a vertical sectional view through a portion of a knitting machine constructed in accordance with the present invention with portions of the machine broken away to more clearly illustrate its construction;

FIG. 2 is a perspective view of the upper portion of ,the knitting machine illustrated in FIG. 1;

FIG. 3 is a transverse sectional view taken on line 33 of FIG. 1;

FIG. 4 is a diagrammatic representation illustrating the operation of the machine of the present invention, showing at the upper portion of the figure the movement of the needles and feeds as seen from the inside of the needle circle, showing in the mid portion of the figure the fabric formed thereby inverted, and as seen from the inside of the upwardly moving web, and show-ing at the lower portion of the figure, the cam tracks controlling the movement of the needles at a reduced scale to enable diagrammatic correlation with the needles shown in the upper portion of the figure; and

FIGS. 5, 6, 7, and 8 show a portion of the needles shown in the upper portion of FIG. 4, as the yarn feed progresses through degrees relative to the needles.

.Referring now to the drawings, and particularly to FIGS. 1 through 3, a hose 10 has a reinforcing fabric 12 knitted about the outer periphery of the hose. The fabric 12 is composed of two tubular webs knitted from separate yarns and on separate sets of needles. The

needles are so arranged in the cylinder that those of one set alternate with those of the other set. Consequently the wales 20 of one web alternate with the wales 30 of the other web about the circumference of the composite fabric.

In the present embodiment of the invention, each web of the composite fabric 12 is formed by four feeds so that in each wale, every fourth needle loop is formed by the same yarn feed. The Web having the wales 20. is formed of four yarns, 21, 22, 23, and 24 which are drawn into needle loops 21a through 24a respectively. The connecting runs 2112 through 24b which are associated with yarns 21 through 24 respectively, lie behind the loops forming the wales 30 of the'other web as more fully set forth hereinafter. The web having the wales 30 is formed in a like manner to the web having the wales 20, comprising four

yarns

31, 32, 33, and 34 with respective needle loops 31a through 34a and associated connecting runs 31b through 34b.

In the present instance, the webs are knit with the needle loops disposed on the rear face of the fabric and the connecting runs on the front face of the fabric. This means that the smooth side of the fabric, that is the jersey knit side, is adjacent the outer periphery of the hose 10. As shown in the drawings, the connecting runs of each adjoining set of wales of each web in any one course pass in front of the needle loops of the intervening wale of the other web.

Referring now to the apparatus shown in FIG. 1, the knitting machine comprises a stationary hollow needle cylinder 101 having a reduced upper section 102 and an enlarged lower section 103. The needles are placed in interiorly grooved vertical needle bars which are retained in the lower section 103 of the. needle cylinder 101 by a clamp 117. Similar needle grooves are provided in the exterior of the upper section 102 in accordance with the conventional practice. Referring to FIGS. 1, 2, and 3, two sets of

needles

120 and 130, in the present instance, eight needles in each set, are retained in the needle grooves by suitable retaining means 104 and define a needle circle. The

needles

120 and 130 are conventional in form, and include the usual hook 140 and latch 150. The

needles

120 and 130 are mounted for vertical reciprocation in the needle grooves and to this end, are provided with

butts

105 and 106 respectively which radially project from the needle shank, and engage in

cam tracks

107 and 108 formed in a cam box, in the present instance a rotary barrel cam 109 which is slidable on the stationary central post 110 of the needle cylinder. Means (not shown) is provided to cooperate with the lower portion 111 of the barrel cam 109 to rotate the same and effect longitudinal reciprocation of the needles in the stationary cylinder. A rotary knitting head 113 is axially aligned with the needle cylinder 101 and is provided to cooperate with the vertically reciprocating

needles

120 and 130 to form a knitted web. The head 113 is rotated synchronously with the barrel cam 109 by conventional drive mechanism (not shown) and includes a depending tubular member 114 which embraces the upper portion of the

needle sets

120 and 130 when the needles are in the stitch clearing position. As is illustrated in FIG. 3, two sets of yarn are fed through body yarn feed apertures in the tubular member 114. The first set of yarn feeds comprises the feed apertures 121- 124 to feed the

body yarns

21, 22, 23, and 24 respectively and the second set of yarn feeds comprises the feed apertures 131134 to feed the body yarns 31 through 34 respectively. As is illustrated in FIG. 1, the knitting head 113 terminates in spaced relation to the needle cylinder 101 to define an annular work slot 116 through which the knitted web may be drawn.

As previously explained if the angle (hereinafter referred to as the pressure angle) which the normal to a cam track makes with the longitudinal axis of a needle exceeds 45 degrees, binding of the needle butts, excessive wear and in many instances smashups occur. Thus heretofore, the number of courses which may be knit during one revolution of the cylinder with respect to the cams Was limited by the number of times that a needle raises or lowers during any one relative revolution of the cylinder, which, as has beenexplained is, in turn, limited by the pressure angle of the cam track.

In order to circumvent this problem, and in accordance with one feature of the invention, a plurality of continuous cam tracks are provided, in the present instance two, axially spaced from each other along the cam box and so arranged as to permit the maximum number of reciprocations during one revolution of the knitting cylinder with respect to the cams without exceeding the pressure angle limitation. As may be notedin FIG. 4, each of the cam tracks, 107 and 108, provides four complete reciprocations of the needles of the

sets

120 and 130 respectively during one revolution of the cam box. It should be noted that if the cam tracks were designed to provide an additional reciprocation of their respective needle sets in one revolution, with the same diameter cam box and the same vertical distance moved in one reciprocation of the needles, the cam tracks would of necessity exceed the pressure angle limitation. Thus the cam track 107 permits the maximum number of reciprocations of the needle set 120, in one relative revolution with respect to said needles, without exceeding the pressure angle limitation of 45 degrees. In a like manner, the cam track 108 associated with the needle set 130 is designed for the maximum number of reciprocations of the needle set 130 without exceeding the pressure angle limitation of 45 degrees. In the present instance, as there are four feeds associated with each set of needles, eight courses of knitted fabric are formed for every revolution of the cam box 109. As is illus- 4 trated in FIG. 1, the

cam tracks

107 and 108 are in out-of-phase alignment such that when a needle, for example in cam track 107, is at the knocking over point, the adjacent needle in cam track 108 is approaching the clearing level. Although the cam tracks have been illustrated in this relation, it should be understood that they may be offset from one another so as to provide a different relationship with respect to the needles. This of course could cause the formation of an entirely different fabric. Thus a plurality of cam tracks, each associated with a separate set of needles and yarn feeds, and each cam track of at least two of the plurality of tracks providing a maximum number of reciprocations of its associated needle set without exceeding the pressure angle limitation, provides the maximum number of courses that may be knit in one relative revolution of the needle cylinder.

In accordance with another feature of the invention, in order to provide a double web in lieu of a double knit, and in order to prevent the needles of any one set 130 from catching the yarn being fed from the yarn feed associated with the other set of needles, radial clearance is provided between the rearward edge of the hook of the needles and and the tubular portion 114 of the rotary knitting head 113. To this end the tubular member 114 has an outer portion 114a through which the yarn is fed, and a coaxial inner portion 114b. The inner portion 11412 has an internal diameter suflicient to allow passage of the reinforced hose therethrough and an external diameter sutficient to permit the hooks of the needles to pass in front of the inner portion 11411:. As is illustrated in FIGS. 1 and 2, the outer periphery of the inner portion 11412 is shaved, thereby defining a passage between the hooks and the inner portion where yarns not associated with the particular needle may pass. It should be noted however that the same result could be achieved by merely spacing the needles radially from the inner portion 1141) so as to provide the necessary yarn clearance between the rearward edge of the hook 140 and the inner portion 114b.

As previously explained the wales 20 of one web alternate with the wales 30 of the other web about the circumference of the composite fabric, each web of the composite fabric 12 being formed by four feeds so that in each wale every fourth needle loop is formed by the same yarn feed. With reference to FIG. 4, the needles of the set 120 are designated 1201, through .1208 for the purposes of identification, each of the needles acting similarly as it is traversed by the rotary knitting head 113. The needles 130 are similarly designated 130-1 through 130-8. It should be noted that the cam tracks shown diagrammatically at 107 and 108 are true developments of the cam tracks on the barrel cam, but are at a reduced scale relative to the needles by reason of the enlarged circumference of the cam with respect to the reduced circumference of the needle circle in the upper section 102 of the cylinder. In order that the needle set 120 forms loops only with the yarns 21 through 24, the elevated portion of the cam track 107 corresponding to the stitch clearing height with respect to the needles, is located in general registry with the yarn feeds 121 through 124.

In a like manner the highest portions of the cam track 108 which correspond to the stitch clearing position of the needle of the set 130, are also in general registry with the yarns 31 through 34 and therefore the yarn feeds 131 through 134. Inthis matter each needle associated with a particular cam track is displaced downwardly to draw a stitch concurrently with the passage of the yarn feed associated with that needle. As a result of this spacing the cam track 107 is exactly degrees out-of-phase with the cam track 108, so that the stitch clearing position of the cam track 107 for example corresponds to the loop forming level or knocking over point of the cam track 108 and vice versa.

FIGS. 5 through 8 illustrate the manner in which fabric is knit on the machine. Each of the figures show four of the needles illustrated in the upper portion of FIG. 4, as the feed and the cams progress through 90 degrees of rotation with respect to the needles. Referring firs-t to FIG. 5, the needle 130-2 is shown moving in a downward direction so as to draw a loop through the preceding wale loop of yarn 33, held on the shank of the needle 130-2. As shown in FIG. 6, wherein the yarn and earns have moved 22% degrees with respect to the needles, the latch of the needle 130-2 has been closed by the Wale loop of yarn 33 and the yarn 33 has been cast from the needle 130-2 with the yarn 32 now engaged in the hook 140 of the needle 130-2. As illustrated in FIG. 7 as the needle 130-2 commences to move towards its maximum height, the yarn 22 is cammed behind the hook 140 of the needle 130-2, because, in accordance with the invention, the needle 130-2 has been radially spaced from the portion 114]) of the knitting head 113, the yarn 22 thereby passing behind the needles hook. As may be seen in FIG. 8 the needle 130-2 now engages with the yarn 31 so as-to draw another loop through the loop of the yarn 32. Thus in one complete rotation of the cam and the knitting head, the needle 130-2 forms Wale loops with all of the yarns associated with the yarns 31 through 34. In a like manner the needles of the set 120 operate upon rotation of the knitting head and the cams so as to form the wales 20 with associated connecting runs which lie behind the needle loops of the wales 30. Thus, the two webs which make up the composite fabric are knitted concurrently on two sets of needles, the needles of one set alternating with the needles of the other set.

Thus, in accordance with the present invention, means are provided wherein a plurality of courses may be knit upon one revolution of the cylinder on a small cylinder circular knitting machine. This is accomplished in accordance with the present invention by providing an additional cam track to circumvent the pressure angle limitation thereby permitting an increased number of knitted courses per relative revolution of the cylinder. Further, in accordance with the present invention, means are provided so as to produce a tubular knitted fabric composed of individual mutually overlying knitted webs to provide a smooth front and back face in the fabric and to improve the burst strength of flexible hose or the like much more rapidly than heretofore known in the art of small cylinder knitting machines.

Although the invention has been described with a certain degree of particularity, it is understood that the present disclosure has been made only by way of example and that numerous changes in the details of construction and the combination and arrangement of parts may be made without departing from the spirit and the scope of the invention as hereinafter claimed.

What is claimed is:

1. A circular knitting machine comprising a hollow needle cylinder and at least two sets of knitting needles slidably mounted thereon, each of said needles having radially projecting butts, a cam box relatively rotatable with respect to said cylinder and having at least two cam tracks the first of which is engagable with the butts of one of said sets of needles and the second of which is engagable with the butts of said other set of needles so as to provide reciprocation of said needles upon relative movement between said cam box and said cylinder, said two cam tracks providing a maximum number of reciprocations of its associated needle-set between stitch-clearing and stitch-drawing levels Without exceeding the pressure angle limitation of 45 degrees, at least two sets of yarn feeds, each of said sets of yarn feeds having the number of yarn feeds equal to the number of reciprocations of one of said needles in one of said sets during one relative revolution of said cam box, each of said sets of yarn feeds adapted to feed yarn to at least its associated set of needles upon relative movement between said yarn feeds and said, needles.

2. A circular knitting machine comprising a hollow needle cylinder and at least two sets of knitting needles slidably mounted thereon, each of said needles having radially projecting butts, a cam box relatively rotatable with respect to said cylinder and having at least two cam tracks the first of which is engagable with the butts of one of said sets of needles and the second of which is engagable with the butts of said other set of needles so as to provide reciprocation of said needles upon relative movement between said cam box and said cylinder, at least two of said cam tracks providing a maximum number of continuous reciprocations of the needles in its associated set between stitch-clearing and stitch-drawing levels without exceeding the pressure angle limitation of 45 degrees, at least two sets of yarn feeds, at least one of said sets of yarn feeds having at least four yarns circumferentially positioned about said cylinder, the number of yarns to be knit equal in number to the number of reciprocations of one of said needles in its associated set during one relative revolution of said cam box, each of said sets of yarn feeds adapted to feed said yarn to one of said sets of needles upon relative movement between said yarn feeds and said needles.

References Cited by the Examiner DONALD W. PARKER, Primary Examiner.

R. FELDBAUM, Assistant Examiner.

Claims

1. A CIRCULAR KNITTING MACHINE COMPRISING A HOLLOW NEEDLE CYLINDER AND AT LEAST TWO SETS OF KNITTING NEEDLES SLIDABLY MOUNTED THEREON, EACH OF SAID NEEDLES HAVING RADIALLY PROJECTING BUTTS, A CAM BOX RELATIVELY ROTATABLE WITH RESPECT TO SAID CYLINDER AND HAVING AT LEAST TWO CAM TRACKS THE FIRST OF WHICH IS ENGAGABLE WITH THE BUTTS OF ONE OF SAID SETS OF NEEDLES AND THE SECOND OF WHICH IS ENGAGABLE WITH THE BUTTS OF SAID OTHER SET OF NEEDLES SO AS TO PROVIDE RECIPROCATION OF SAID NEEDLES UPON RELATIVE MOVEMENT BETWEEN SAID CAM BOX AND SAID CYLINDER, SAID TWO CAM TRACKS PROVIDING A MAXIMUM NUMBER OF RECIPROCATIONS OF ITS ASSOCIATED NEEDLE SET BETWEEN STITCH-CLEARING AND STITCH-DRAWING LEVELS WITHOUT EXCEEDING THE PRESSURE ANGLE LIMITATION OF 45 DEGREES, AT LEAST TWO SETS OF YARN FEEDS, EACH OF SAID SETS OF YARN FEEDS HAVING THE NUMBER OF YARN FEEDS EQUAL TO THE NUMBER OF RECIPROCATIONS OF ONE OF SAID NEEDLES IN ONE OF SAID SETS DURING ONE RELATIVE REVOLUTION OF SAID CAM BOX, EACH OF SAID SETS OF YARN FEEDS ADAPTED TO FEED YARN TO AT LEAST ITS ASSOCIATED SET OF NEEDLES UPON RELATIVE MOVEMENT BETWEEN SAID YARN FEEDS AND SAID NEEDLES.