US3728901A

US3728901A - Apparatus for reversing the traverse of the cam carriage of an automatically operating flat knitting machine

Info

Publication number: US3728901A
Application number: US00175169A
Authority: US
Inventors: K Essig
Original assignee: H Stoll GmbH and Co KG
Current assignee: H Stoll GmbH and Co KG
Priority date: 1970-08-27
Filing date: 1971-08-26
Publication date: 1973-04-24
Anticipated expiration: 1990-04-24
Also published as: DE2042500A1; DE2042500C3; DE2042500B2; FR2106070A5; GB1321507A; CH527945A

Abstract

A changeover device for a flat knitting machine of the type wherein the carriage is reciprocated through a traverse type gear casing having roll ring gearing for converting rotary movement into linear displacement has a double-armed changeover lever pivotally mounted on the gear casing so as to vary the orientation of the roll ring gearing members therein. The lever is provided with rollers at its ends, and one or the other of these rollers is pressed against a longitudinally extending abutment rail during traverse of the casing and carriage. An inclined braking bar is disposed at each end of the traverse path for encountering an approaching roller to thereby pivot the changeover lever in the sense to bring about a continuing reduction in speed of traverse. A thrust device is released shortly before the carriage comes to rest, and thrusts the changeover lever beyond its dead center position to reverse the carriage traverse. The abutment rail is adjustable to vary the angular setting of the changeover lever, and hence the traverse speed. The braking bars are longitudinally adjustable, and means are provided for biasing the changeover lever oppositely to its pivotal movement until it reaches a predetermined distance beyond its dead center position so as to ensure continued traverse in the same direction after the lever is moved to dead center to stop the traverse.

Description

a United States Patent 1191 Essig [75] Inventor: Karl Essig, Reutlingen. Germany [73'] Assignee: H. Stoll & Company, Stollweg, Ger

' many [22] Filed: Aug. 26, 1971 [21] Appl. No.: 175,169

{30] Foreign Application Priority Data Aug. 27, 1970 Germany ..P 20 42 500.7

[52] US. Cl. ..74/27, 66/126, 74/25 [51] lnt.Cl ..Fl6h 21/16 [58] Field of Search ..74/27, 25; 66/126, 66/130 [56] References Cited UNITED STATES PATENTS 402,674 5 1ss9 Judson ....74 25 2,578,026 12/1951 Taylor ..74/25 2,940,322 6/1960 Uhing ..74/25 2,987,268 6/1961 Haugwitz. ..74/25 3,443,443 5/1969 Spence.... ..74/25 3,473,393 10/1969 Zaruba.... ..74/25 2,253,439 8/1941 MacKay Intro/130 2,273,301 2/1942 Tuchscherer et al.. ...66/130 2,598,986 6/1952 Fegley ...66/l26 3,050,969 8/1962 Me Carthy ...66/130 2.912.840 1 1/1959 Cobert ..66/130 11 1 3,728,901 1451 Apr. 24, 1973 Primary Eraminer-Charles .1. Myhre Assistant ExaminerWesley S. Ratliff, Jr. Attorney-Lars0n, Taylor & Hinds 1 57] I ABSTRACT A changeover device for a flat knitting machine of the type wherein the carriage is reciprocated through a traverse type gear casing having roll ring gearing for converting rotary movement into linear displacement has a double-armed changeover lever pivotally mounted on the gear casing so as to vary the orientation of the roll ring gearing members therein. The lever is provided with rollers at its ends, and one or the other of these rollers is pressed against a longitudinally extending abutment rail during traverse of the casing and carriage. An inclined braking bar is disposed at each end of the traverse path for encountering an approaching roller to thereby pivot the changeover lever in the sense to bring about a continuing reduction in speed of traverse. A thrust device is released shortly before the carriage comes to rest, and thrusts the changeover lever beyond its dead center position to reverse the carriage traverse. The abutment rail is adjustable to vary the angular setting of the changeover lever, and hence the traverse speed. The braking bars are longitudinally adjustable, and means are provided for biasing the changeover lever oppositely to its pivotal movement until it reaches a predetermined distance beyond its dead center position so as to ensure continued traverse in the same direction after the lever is moved to dead center to stop the traverse.

12 Claims, 5 Drawing Figures SHEH 2 (if 3 PATENTEDAPR 24 I975 3v 72.8 901 sum 3 BF 3 WKENTOP APPARATUS FOR REVERSING TI-IE TRAVERSE OF THE CAM CARRIAGE OF AN AUTOMATICALLY OPERATING FLAT KNITTING MACHINE FIELD OF THE INVENTION This invention relates to means for effecting reversals in the traverse of the cam carriage of an automatically-operating flat knitting machine.

BACKGROUND AND SUMMARY OF THE INVENTION 1 It has already been proposed,,for example, in US. Pat. No. 2,940,322 to Uhing (German Patent Specification l,057,4l l to provide a roll ring-operated friction gearing, which converts a rotary movement into a linear displacement, as the means for driving such a flat knitting machine. A drive of this character has the advantage over a conventional chain drive employed for a flat knitting machine in as much that variations in the length of stroke and variations of the speed of drive of the cam carriage can be implemented by the roll ring gearing itself. However, it is necessary that the point at which the cam carriage reverses shall be accurately determined on each occasion. This means that there must be no dead over-run at the reversing points of the carriage. This is important because various functions of the machine to form stitches and for patterning purposes have to take place at the appropriate dead center position ofthe cam carriage.

The object of the present invention is to provide, in an automatically operating flat knitting machine, an improved changeover device enabling the reversal of the cam carriage to take place at any selected point in the travel of the carriage while completely avoiding any dead over-run, that is to say in such a way as to obtain a sharp decisive reversal.

The improved changeover device generally in accordance with a preferred embodiment of the invention is characterized in that the gear casing, which brings about the displacement of the cam carriage of the machine, is equipped with a double-armed changeover lever which is provided with two rollers, the mean central axis of this lever being disposed in the operative condition at an angle a or ,B to the central axis of the machine in such a way that one of the said rollers is at any time pressed against an abutment rail, disposed in the longitudinal direction of the machine, by a springloaded lever which is pivotally coupled to said changeover lever, and that use is made of braking bars over which the other of the rollers runs, the changeover lever being thereby pivoted to bring about a continuing reduction in speed of the carriage travel, and further a locking pawl is released by the last mentioned roller shortly before the carriage comes to rest and releases a spring-loaded thrust lever to produce a further pivoting of the changeover lever beyond its dead center, and thus initiate a reversal of the carriage. The abutment rail, which extends in the longitudinal direction of the machine and the distance of which from the axis of the changeover lever determines the carriage speed, is adjustable parallel to the longitudinal axis of the machine. The changeover lever advantageously cooperates with a rocking lever having a tip which has surfaces relatively arranged in wedge fashion and which,- when the changeover lever is swung over, jumps a counter tip provided on a spring loaded rocking or thrust lever, and this counter tip insures the return of the changeover lever to its starting position from its dead center position.

DESCRIPTION OF THE DRAWINGS In order that the invention may be more clearly understood and readily carried into practical effect, one specific constructional embodiment thereof will now be described, by way of example with reference to the accompanying drawings, wherein:

FIG. 1 is a plan view of the gear casing with the operating members and reversing elements,

FIG. 2 is a view, partly in section, taken at to FIG. 1 and showing the parts depicted in the latter,

FIG. 3 is an enlarged view of the operating members when the carriage is moving in a direction opposite to that shown in FIG. 1,

FIG. 4 depicts the changeover lever of the assembly during the period of run-up to the reversing elements,

and

FIG. 5 shows the changeover lever at a time when the machine is stopped to rectify a fault in the operation thereof.

Referring to the drawings, it will be seen that a pin 3 is rotatably mounted in a gear casing 1 in which are arranged the roll rings (not shown) which are pressed against the drive shaft 2. This pin 3 is so coupled to the roll rings that angular adjustment'thereof determines the angular setting of the roll rings at that time to the drive shaft 2, and at the same time the speed and direction of travel of the carriage. Angular adjustment of pin 3 is performed by a changeover (reversing) lever 4 rigidly connected to the said pin. This lever 4 is a double-armed lever, and

rollers

5, 6, are mounted for free rotation at the ends of the two arms thereof. A loading lever 7 is pivotally connected to onearm of the changeover lever 4 through the medium of a pin 8 and in such a way that this loading lever 7 co-operates with the changeover lever 4 to provide a crank which urges one of the

rollers

5, 6 against an abutment rail 15 in one or other of its operative positions. This is accomplished by providing the loading lever 7 with a slot 9 in which is received a pin 10 rigid in casing 1, whereby the lever 7 is displaceable and pivotable. Furthermore, the pin 10 has a cross-piece 11 freely rotatable thereon. The appropriate ends of two

tension springs

12, 13 are connected to respectively opposite ends of the cross-piece 11. The opposite ends of these springs are connected to a pin 14 at the end of lever 7'. Thus,

tension springs

12, 13 serve not only to bring about an adjustment of the changeover lever 4 to incline it in the operating position but also to apply one of the

rollers

5, 6 against the abutment rail 15 which extends in the longitudinal direction of the machine. This abutment rail is adjustable in the transverse direction of the machine, that is to say, in the direction of arrow A (FIGS. 1 and 4) by any suitable means.

Changeover lever 4 is actuated by operating parts 16 to 24 which are adjustable longitudinally of the machine at the two sides of the gear casing 1. A braking bar 17, inclined to the longitudinal axis of the machine, is secured to each of two base plates 16 (shown in chain dotted lines in FIG. 1). Each bar 17 is disposed so as to enable the relevant approaching

roller

5, 6 of the changeover lever 4 to run along its edge. Thus, when one of these

rollers

5, 6 runs on to the edge of a braking bar 17, the lever 4 is pivoted by the said bar out of its inclined disposition into one in which it lies along the longitudinalaxis of the machine. The inclination of the braking bar 17 is such as to produce this transition of the changeover lever 4 relatively gradually. A doublearmed lever 19, pivotally mounted on a pin 18, and spring biassed by 19'', is disposed above the braking bar 17(see FIG. 2) and has an outer edge 19 which extends in the said direction as and alined with the run-on edge 17 of the braking bar 17 during the travel of the carriage, that is to say, in the operative position of the double-armed lever 19. This basic position of each spring-loaded double-armed lever 19 is determined by a pawl 20, also spring-loaded, which is pivotally mounted on a pin 20 secured in the corresponding base plate 16. Each such pawl 20 is influenced by a tension spring 21 and is provided with a nose 22 which releasably engages the corresponding double-armed lever 19 in any convenient and conventional manner. For instance, nose 22 might engage a short pin or projection on lever 19, the particular mode of engagement being irrelevant to the invention. The end of each pawl 20 projecting beyond the corresponding lever 19 has-an abutment surface 23 against which runs that

roller

5, 6 of the changeover lever 4 which at the time meets it (Position II, FIG. 4). In addition, a guideIbar 24 is secured to each of the base plates 16, this being disposed opposite the braking bar 17 and the doublearmed lever 19 concerned and extending at an inclination opposite to these. Finally, a one-armed rocking lever 25 is mounted for free rotation on the pin 3 about the changeover lever 4, the said rocking lever having at its free end a tip 26 with surfaces 26' and 26" arranged in wedge configuration (FIG- 3). The distance which can be traversed by the rocking lever 25 is regulated by set

screws

27, 28 on the changeover lever 4. A counter tip 29, having surfaces 29' and 29", is-fastened to a thrust lever 30 pivotally mounted on a pin 30' fixed in the casing l. The thrust lever 30 is pulled by a tension spring 31' against an abutment pin 32. An adjusting screw 33 in the thrust lever 30 at the level of the abutment pin 32 caters for accurate setting of the lever 30.

The herein described changeover device operates as follows:

In the situation illustrated in FIGS. 1 and 4, in which roller of the changeover (reversing) lever 4 bears against the abutment rail 15, the changeover lever 4 is inclined rearwards so that there is an angle'a between its central axis and the direction of the carriage travel, i.e. the longitudinal axis of the machine (see FIG. 4). In this situation a carriage stroke from left to right is performed. Thus, roller 6 of the changeover lever 4 is the approaching roller which contacts the braking bar 17 before the-travel of the carriage has ceased (Position I FIG. 4).

Rollers

5 and 6 are sufficiently thick to enable them to be operated both by the braking bar 17 and also by the double-armed lever 19. Roller 6, running over braking bar 17, thus pivots the double-armed lever 4 in such a way that angle a gradually becomes narrower, and the concomitant turning of pin 3, and the variation of the angular positions of the ring 'rolls thereby occasioned, increasingly reduces the speed of travel of the carriage in the machine. Shortly before the speed of the carriage becomes zero, roller 6 of changeover lever 4 strikes abutment surface 23 of spring loaded pawl (Position II, FIG. 4). This disengages the nose 22 of the pawl from the lever 19 and frees the spring biassed double-armed lever 19 and, under the pivoting action of lever 19 by tension spring 19", the

roller 6 shifts the changeover lever 4 beyond its dead longitudinal axis of the machine, has now moved to angle B (the position shown in dotted-lines), and the gear casing 1, by reason of the accompanying pivotal movement of the roller rings, moves in the opposite direction, that is to say, from right to left, whereupon it repeats the procedure described above but in the appropriate sense. In the changeover or reversal itself takes place when the pawl 20 releases, that is to say, always at a point which is accurately determined. A return and fresh engagement of the double-armed lever 19 with the pawl 20 is brought about by one of two drive rollers 34 provided on the gear casing l, the leading one of these drive rollers engaging behind the double-armed lever 19 in the reverse condition and restoring this lever 19 at the commencement of a fresh carriage stroke.

The size of angles a and B, and thus the speed and direction of the carriage at any time, is determined by the position of the abutment rail 15. This is used to provide for a continuation of the carriage travel in the direction of travel which has already commenced, after a stoppage of the machine, e.g. caused by a fault. When such a fault occurs, the abutment rail 15 will be shifted in the direction of arrow A'toward the gear casing, that is, parallel to the longitudinal axis of the machine, by suitable means which form no part of the invention, until the changeover lever 4 pivoted thereby is disposed in this longitudinal direction of the machine; that is to say, the angles a and B become nil and the roll rings apply no further thrust and the cam carriage therefore is stationary. In the conditions illustrated in FIG. 5, surface 26' of tip 26 bears against surface 29" of the counter tip 29. The rocking lever 25 thus continues to press roller 6 against the abutment rail 15 so that when the latter returns to its starting position the changeover lever 4 returns to its previous position, and the travel of the carriage continues in the original direction. When I the carriage stroke is reversed, and an opposite inclination of the changeover lever 4 isthus brought about, the tip'26, and also the tip 29 of the thrust lever 30,.are pushed back so that the tip 26 is disposed in front of tip 29 during the ensuring stroke of the carriage and in the event of a fault then occuring the surface 26" of tip 26 will be applied against surface 29 of the tip 29. As a result, roller 5 of the changeover (reversing) lever 4 bears against abutment rail 15 and also returns with this into the previous'disposition so that this also can continue the carriage stroke, previously commenced, from this position.

The embodiment of the invention which has been described and illustrated is a constructional one through which the effects sought can be achieved by purely mechanical means. It is, however, also possible to employ other operating members acting in an analogous fashion for the same purpose/in particular it is feasible to-use electrically or electro-mechanicallyoperated, means to produce a reversal of the carriage movement at accurately-determined points. To this end it would, for example, only be necessary to make the pawl the armature of an electromagnet and to operate this at the appropriate times.

lclaim:

1. In an automatically operating flat knitting machine having a cam carriage driven through roll ring friction gearing disposed in a gear casing such that the speed I and direction of traverse of the gear casing and the cam carriage depend upon the orientation of the roll ring gearing members relative to a dead center position at which no traverse occurs, a changeover device comprising a double-armed pivotally mounted changeover lever carried by said gear casing for varying the orientation of the gearing members about their dead center positions in accordance with its pivotal setting about a corresponding dead center position, rollers mounted on the opposite ends of said changeover lever, an abutment rail disposed in the longitudinal direction of the machine to provide a guide surface for said rollers as the gear casing is traversed back and forth, resilient means for pressing either of said rollers against said abutment rail when said changeover lever is pivoted past its dead center position, a braking bar located at each end of the traverse path of the gear casing and located and oriented so as to encounter one of said rollers and pivot the changeover lever in the sense to bring about a relatively gradual continuing reduction in speed of the casing and carriage, and automatic operable means for relatively rapidly pivoting said changeover lever in the same sense and beyond its dead center position shortly before the carriage and easing come to rest, thus initiating a reversal of the carriage traverse.

2. Apparatus as claimed in claim 1 wherein said automatically operable means comprises a thrust lever biased to pivot said changeover lever in said sense, and release means responsive to the position of the casing and carriage for releasing said thrust lever.

3. Apparatus as claimed in claim 3 wherein said release means comprises a locking pawl in the path of said one of said rollers for releasing said thrust lever when encountered by said one of said rollers.

4. Apparatus as claimed in claim 1 wherein said abutment rail is adjustable parallel to the longitudinal axis of the machine so as to vary the pivotal setting of said changeover lever and thus vary the speed of the carriage in accordance with the distance between said rail and the pivot axis ofsaid changeover lever.

5. Apparatus as claimed in claim 4 further comprising restoring means for biasing said changeover lever oppositely to its direction of pivotal movement until said changeover lever pivots a predetermined distance past its dead center position, whereby said changeover lever can be moved to dead center position to stop the carriage traverse and will be automatically restored to its starting position to resume carriage traverse in the same direction upon resumption of operation.

6. Apparatus as claimed in claim 5 wherein said restoring means comprises a rocking lever mounted for limited pivotal movement relative to said changeover lever and having a wedge shaped tip, and a pivotally mounted spring loaded thrust lever carrying a counter tip in the path of said wedge shaped tip such that the wedge shaped tip must force the counter tip and the thrust lever pivotally to effect a complete reversal of inclination of said changeover lever, whereby said thrust lever and said counter tip exert a restoring bias on said wedge shaped tip and said change-over lever until said changeover lever moves past dead center by a distance determined by the limited pivotal movement of said wedge shaped tip relative to said changeover lever.

7. Apparatus as claimed in claim 1 wherein each said braking bar is mounted on a base plate adjustable in the longitudinal direction of the machine to permit varying the stroke of the carriage.

8. Apparatus as claimed in claim 7 wherein each base plate carries a guide bar oriented generally oppositely from its associated braking bar for guidingly receiving said one of said rollers and effecting a relatively gradual increase in speed of the casing and carriage after said changeover lever has been pivoted post its dead center position by said automatically operable means.

9. Apparatus as claimed in Claim 2 wherein said thrust lever is pivotally mounted adjacent to and parallel with said braking bar and has an edge which extends with the roller-encounteringedge of said braking bar so that the roller can be in engagement with both edges simultaneously when the thrust lever is in its unreleased position.

10. Apparatus as claimed in claim 2 further comprising means for automatically returning said thrust lever to its unreleased state after completion of traverse reversal.

II. [n a flat knitting machine having a cam carriage which is traversed back and forth by roll ring friction gearing disposed in a gear casing and cooperating with a rotary drive shaft such that the traverse direction and speed of the carriage and the casing depend upon the variable orientation of 'the roll ring gearing members relative to the shaft about a dead center position at which no traverse occurs, traverse changeover apparatus comprising a changeover lever pivotally mounted on said casing for varying the orientation of the gearing members in accordance with its pivotal setting about a corresponding dead center position, resilient means for biasing said changeover lever toward either of its maximum limit positions away from said dead center position so as to effect maximum traverse speed in either direction, a braking bar located at each end of the traverse path of the casing for encountering the changeover lever and pivotally guiding it toward its dead center position to effect a continuing reduction in traverse speed, and an automatically operable thrust member for thrusting said changeover lever past its dead center position at a predetermined point in the traverse of said casing during said continued reduction in traverse speed and shortly before the carriage comes to rest.

12. Apparatus as claimed in claim 11 wherein said change-over lever is a double-armed lever, and further comprising an abutment rail extending parallel to the traverse path of the casing so that one or the other end when the lever is in either of its maximum limit positions, and wherein said thrust'member is a cocked member releasable by said changeover lever and located adjacent said braking bar.

Claims

1. In an automatically operating flat knitting machine having a cam carriage driven through roll ring friction gearing disposed in a gear casing such that the speed and direction of traverse of the gear casing and the cam carriage depend upon the orientation of the roll ring gearing members relative to a dead center position at which no traverse occurs, a changeover device comprising a double-armed pivotally mounted changeover lever carried by said gear casing for varying the orientation of the gearing members about their dead center positions in accordance with its pivotal setting about a corresponding dead center position, rollers mounted on the opposite ends of said changeover lever, an abutment rail disposed in the longitudinal direction of the machine to provide a guide surface for said rollers as the gear casing is traversed back and forth, resilient means for pressing either of said rollers against said abutment rail when said changeover lever is pivoted past its dead center position, a braking bar located at each end of the traverse path of the gear casing and located and oriented so as to encounter one of said rollers and pivot the changeover lever in the sense to bring about a relatively gradual continuing reduction in speed of the casing and carriage, and automatic operable means for relatively rapidly pivoting said changeover lever in the same sense and beyond its dead center position shortly before the carriage and casing come to rest, thus initiating a reversal of the carriage traverse.

4. Apparatus as claimed in claim 1 wherein said abutment rail is adjustable parallel to the longitudinal axis of the machine so as to vary the pivotal setting of said change-over lever and thus vary the speed of the carriage in accordance with the distance between said rail and the pivot axis of said changeover lever.

8. Apparatus as claimed in claim 7 wherein each base plate carries a guide bar oriented generally oppositely from its associated braking bar for guidingly receiving said one of said rollers and effecting a relatively gradual increase in speed of the casing and carriage after said changeover lever has been pivoted past its dead center position by said automatically operable means.

9. Apparatus as claimed in Claim 2 wherein said thrust lever is pivotally mounted adjacent to and parallel with said braking bar and has an edge which extends with the roller-encountering edge of said braking bar so that the roller can be in engagement with both edges simultaneously when the thrust lever is in its unreleased position.

11. In a flat knitting machine having a cam carriage which is traversed back and forth by roll ring friction gearing disposed in a gear casing and cooperating with a rotary drive shaft such that the traverse direction and speed of the carriage and the casing depend upon the variable orientation of the roll ring gearing members relative to the shaft about a dead center position at which no traverse occurs, traverse changeover apparatus comprising a changeover lever pivotally mounted on said casing for varying the orientation of the gearing members in accordance with its pivotal setting about a corresponding dead center position, resilient means for biasing said changeover lever toward either of its maximum limit positions away from said dead center position so as to effect maximum traverse speed in either direction, a braking bar located at each end of the traverse path of the casing for encountering the changeover lever and pivotally guiding it toward its dead center position to effect a continuing reduction in traverse speed, and an automatically operable thrust member for thrusting said changeover lever past its dead center position at a predetermined point in the traverse of said casing during said continued reduction in traverse speed and shortly before the carriage comes to rest.

12. Apparatus as claimed in claim 11 wherein said change-over lever is a double-armed lever, and further comprising an abutment rail extending parallel to the traverse path of the casing so that one or the other end of said changeover lever will normally be biased into engagement with said rail by said resilient means to define said maximum limit positions, the dead center position of said changeover lever occurring when its longitudinal axis is parallel to said abutment rail, said lever axis forming acute angles with said abutment rail when the lever is in either of its maximum limit positions, and wherein said thrust member is a cocked member releasable by said changeover lever and located adjacent said braking bar.