US3355912A

US3355912A - Presser operating means for warp knitting machines

Info

Publication number: US3355912A
Application number: US479383A
Authority: US
Inventors: John D Wenrich
Original assignee: Textile Machine Works
Current assignee: Textile Machine Works
Priority date: 1965-08-13
Filing date: 1965-08-13
Publication date: 1967-12-05
Anticipated expiration: 1984-12-05

Description

Dec. 5, 1967 J. D. WENRICH 3,355,912

PRESSER OPERATING MEANS FOR WARP KNITTING MACHINES Filed Aug. 15, 1965 2 Sheets-Sheet 1 TLE L if a; 6'8 6',

7/ 3; 97 90 55 7 63 85 86 -6/ 7 1 AL [I I Dec. 5, 1967 J. D. WENRICH 3,355,912

PRESSER OPERATING MEANS FOR WARP KNITTING MACHINES Filed Aug. 13, 1965 2 Sheets-Sheet United States Patent 3,355,912 PRESSER OPERATING MEANS FOR WARP KNITTING MACHINES John D. Wenrich, Fleetwood, Pa., assignor to Textile Machine Works, Wyomissing, Pa., a corporation of Pennsylvania Filed Aug. 13, 1965, Ser. No. 479,383 8 Claims. (Cl. 66-86) ABSTRACT OF THE DISCLOSURE Operating means for adjusting the operating path of the needle beard presser of a warp knitting machine including a presser shaft having eccentric portions and means for rotating the shaft to adjust the eccentric portions between first and second positions corersponding to starting speed and maximum operating speed of the machine, respectively.

This invention relates to warp knitting machines and more particularly to an improved needle beard presser operating means for such machines.

In warp knitting and like machines which are operated at high speeds, the needle beard presser bar is carried on support levers which are supported for rocking movement on a shaft carried in fixed position in the machine and the support levers are connected by links to a series of levers operated by a cam or eccentric shaft of the machine by means of which the presser bar is operated in timed relation to the needles, sinkers and yarn feeding means in forming fabric on the machine. Conventionally, the operating means for the presser bar is initially adjusted so that the presser bar reaches its normal beard closing position to close the beards over the new yarn lapped around the shanks of the needles before the beards pass through the previously formed stitches held in the throats of the sinkers. During acceleration of the machine from zero to operating speed the play in the joints con necting the various links and levers combined with deflection in these parts causes overtravel of the presser bar at the beard closing end of its movement. While some overtravel of the presser bar is permissible without materially affecting the needle beard pressing action of the bar, this overtravel gradually increases in extent as the speed of the machine is increased and eventually reaches a degree that causes defective stitch formation. In practice it was found that at operating speeds up to 900 courses per minute the presser bar overtravels approximately eighteen-thousandths of an inch (0.018) which is the accepted limit of overtravel at which the machine will continue to operate to produce acceptable fabric. In attempts to increase the operating speed of the machine above 900 c.p.m. without exceeding the acceptable limit of overtravel the initial press was slightly retarded but this merely caused defective presser action at the slower speeds without permitting any material increase in the maximum operating speed of the machine.

It is an object of the invention to provide means in a warp knitting machine for controlling the operation of the needle beard presser mechanism which will overcome the above noted and other objections to prior beard presser mechanism for such machines.

Another object of the invention is the provision of means in a warp knitting machine for adjusting the operating path of the needle beard presser to thereby provide substan-. tially the same operating relationship between the beard presser and needles at zero and maximum operating speeds of the machine.

A further object of the invention is the provision of means in a warp knitting machine for adjusting the operating path of the needle beard presser in relationship to the operation of the needles between starting or zero speed and maximum operating speed of the machine, which means includes a shaft having eccentric portions for supporting the beard presser for operation and means for rotating the shaft to adjust the eccentric portions between a first position to control the path of the beard presser at starting speed of the machine and a second position to control the path of the beard presser at maximum operating speed of the machine.

With these and other objects in view which will become apparent from the following detailed description of the illustrative embodiment of the invention shown in the accompanying drawings, the invention resides in the novel elements of construction and combination of parts in cooperative relationship as hereinafter particularly pointed out in the claims.

In the drawings:

FIG. 1 is a view of mechanism for operating the needle beard presser bar of a warp knitting machine in accordance with the invention;

FIG. 2 is a view of the means for adjusting the operat ing path of the needle beard presser according to the invention;

FIG. 3 is an enlarged view of the support shaft for the beard presser and diagrammatically indicating different adjusted positions to which the shaft is moved;

FIG. 4 is a diagrammatic view on an enlarged scale of the operating paths followed by the yarn feeding and the fabric forming means of the machine;

FIG. 5 is a view diagrammatically illustrating the normal and retarded operating paths of presser bars; and

FIG. 6 is a view diagrammatically illustrating a portion of the electrical circuit of the machine for operating the mechanism of the invention.

Referring to FIG. 1 of the drawings there is shown conventional fabricating means of a warp knitting machine including a row of spring bearded needles 10 carried in a needle bar 11, sinkers 12 which are mounted on a bar a portion of which is shown at 15, a presser member 16 for closing the beards of the needles, a bar 17 on which the presser member is mounted, and yarn guides 20 which are mounted for movement through the row of needles and along the row of needles to lap the yarns fed thereby around the needles in the usual manner. The needle bar 11 is supported on levers 21 which are mounted for rocking movement on a fixed shaft 22 whereby the needles 10 are adapted to be operated along a path 23 (FIG. 4) from a low or knockover position to a high position at which time the yarn guides 20 are moved back and forth through the needles to lap the yarns carried thereby around the shanks of the needles below the beards thereof. The needles, after receiving yarn from the guides, are lowered along the path 23 to catch the newly received yarn beneath the beards thereof and the beards are closed by the presser bar 16 until the tips of the beards pass through the previously formed stitches held in the throats of the sinkers. The sinkers are then retracted to permit the needles to draw stitches of the yarn held beneath the beards through the previously formed stitches held on the knockover surfaces of the sinkers and to cast off or knockover the latter stitches from the needles. The means for operating the needles 10, sinkers 12 and guides 20 in the manner set forth forms no part of the invention and is not shown herein.

In accordance with the instant invention the bar 17 for the presser member 16 is carried on levers 25, only one of which is shown, which are loosely supported for rocking movement on a shaft 23 mounted in bearing members 29 forming a part of the framework of the machine. Each lever is pivotaily connected by an adjustable link to the free end of a first rock lever 31 pivotally mounted on a first rock shaft 32 mounted in fixed position in the machine. Intermediate the free end of the lever 31 and shaft 32, the lever 31 is pivotally connected to one end of a link 35. The other end of link 35 is pivotally connected to a lever 36 having one end mounted for rocking movement on an eccentric portion 4i) of a shaft 41 mounted for rotation in the framework of the machine. The eccentricity of the portion 46 of shaft 41 is such as to move the presser member 16 at a relatively slow speed to a position adjacent the row of needles and to then rapidly accelerate the speed of movement of the presser member as it completes its beard closing movement during each rotation of the shaft 41. The other end of the lever 36 is pivotally connected to the free end of a second rock lever 45 pivotally mounted on a second rock shaft 46 carried in fixed position in the framework of the machine. The shaft 41 is the driving shaft of the machine and is driven by a motor shown diagrammatically at 42 in FIG. 6 through driving connections not shown herein and forming no part of the instant invention.

Normally, the relationship of the various levers and links of the operating linkages connecting the shaft 41 and the levers 25 are initially adjusted during manual operation of the machine so that the presser member 16 is moved by the eccentric portions 46 of the shaft 41 along an arcuate path 47, indicated in full line in FIG. 5, between a retracted position indicated at point 48 and a normal beard closing position indicated at point 49 to close the beards of the needles after the tips of the beards pass below the yarn on the shanks of the needles which is supported at this time on the upper surfaces of the sinkers. Thereafter during power operation of the machine as the machine is accelerated from zero speed to maximum operating speed, which is hereinafter referred to as normal operating speed, deflection in the parts of the operating linkage causes the presser member to overtravel thereby advancing the beard closing action. In actual practice the normal operating speed of the machine is approximately 900 knitting cycles per minute or 900 c.p.m. and the overtravel of the presser member at the normal operating speed is approximately eighteen-thousandths of an inch to a point indicated at 49a which is the limit of overtravel at which the machine will operate to produce acceptable fabric. When the speed of the machine is increased above the normal speed of 900 c.p.m. the overtravel of the presser member also increases to gradually advance the beard closing action to an extent that causes the beards to damage the yarn lapped around the shanks of the needles or to close the beards before the tips thereof reach the yarn.

In order to permit operating speeds above the normal operating speed of the machine in accordance with the invention, the operating path of the presser member is adjusted to retard the beard pressing action thereof to an extent substantially equal to the acceptable limit of overtravel of the presser member as the machine is accelerated from zero to normal operating speed. For this purpose the shaft 28 is mounted for oscillating movement in the bearing members 29 and the levers 25 are mounted for oscillating movement on eccentric portions 50 of the shaft. The center of the eccentric portions 50 is offset a distance a, which is approximately one-eighth inch, in relationship to the center of the main axis of the shaft 28 and is initially adjusted to an angular position b which is approximately eighteen degrees, from a vertical center line x through the axis of the shaft 28, as shown in FIG- URE 3, to cause the presser member 16 to move between its

positions

58 and 49 during oscillating movement of the levers 25. The portions 50 of shaft 28 are normally maintained in the position b when the machine is stopped by engagement of a set screw 51 adjustably carried in a lever 52 secured to the shaft with a bracket 53 carried on a fixed part 54 of the machine (FIGURE 2). A

spring 55 connected between the lever 52 and a part of the machine frame tends to maintain the set screw 51 in engagement with the bracket 53.

During acceleration of the machine from Zero to the normal operating speed of 900 c.p.m. the lever 52 is adapted to be turned counter-clockwise from its position when the set screw 51 is in engagement with the bracket 53 to a position that turns the shaft 28 and thereby shifts the center of the eccentric portions 59 and the center of oscillating movement of the levers 25 through an angular distance of aproxirnately three degrees to a position 0 (FIGURE 3). This retards the movement of the presser member 16 and causes the levers 25 to move the presser member along an arcuate path 57 between an adjusted beard closing point 58, which is substantially coincident with the normal beard closing point 49, and a retracted position indicated at 59, the path 57 between

points

58 and 59 being substantially equal to the arcuate path 47 between the points 48 and 49a. Although during operating speeds above 900 c.p.m. there is again some overtravel of the presser member beyond the adjusted beard closing point 58, this overtravel will remain within the acceptable normal limit of overtravel until machine operating speeds up to 1800 c.p.m. are attained.

For so moving the lever 52 and eccentric portions 50 of the shaft 28 to shift the center of oscillating movement of levers 25 to the position 0 the lever 52 is pivotally connected by an adjustable link 60 to a core member 61 of a solenoid 62 suitably carried in fixed position on the bracket 53. The solenoid 62 is in the electrical circuit for the motor 42 (FIGURE 6) including main conductors of a three-phase source of electrical energy indicated diagrammatically at 66 which are connected to

buses

67, 68 and 69 through a main switch 70. The

buses

67, 68 and 69 are connected to the main operating windings of the motor 42 through leads 74 which pass through stationary contacts 71 and movable contacts 72 of a switch or relay. The movable contacts 72 are carried on a core member 75 which is adapted to be operated by a coil or winding 76 when the coil is energized to move the movable contacts 72 into engagement with the stationary contacts 71 to close the circuit to the motor 42. The core member 75 is biased by a spring 77 in a direction to disengage the stationary and movable contacts when the coil is deenergized.

The coil 76 is in a control circuit including a transformer 80 which is connected to

buses

67 and 68 and is adapted to reduce the voltage from the main conductors 66 to that required in the control circuit. The transformer is connected by a lead 81 through stationary contacts 82 and a movable contact 83 carried on a stop button 85 of a start and stop switch 86, these stationary and movable contacts being normally biased to closed position (FIGURE 6). From the stationary contacts 82 the circuits for the coil continues through stationary contacts 87 and a movable contact 90 which is connected to the core member 75 and through a lead 91 to

stationary contacts

92 and 95 and a normally disengaged movable contact 96 carried by a start button 97 of the switch 86. The coil 76 is connected by a lead 160 to the lead 91 and by a lead 101 to the transformer 80. When the circuit to the motor 42 is to be energized to start the machine the start button 97 is operated to close the circuit through

stationary contacts

92 and 95 to energize the coil 76 to operate the core member 75 to close the circuit through stationary contacts 71 to the motor. Also at this time the circuit through stationary and

movable contacts

87 and 90 is closed to hold the circuit through the coil 76 when the start button 97 is again released.

The control circuit also includes a timer device 102 which is connected by leads 105 to the lead 91 and to the transformer 80. The timer device 162 is connected by a lead 106 through an operating coil or winding 107 of the solenoid 62 to the bus 68 and by a lead 110 to the bus 69. The timer device 102 may be of any commercial type, such as the Agastat Timer manufactured by the Elastic Stop Nut Corp. of Elizabeth, New Jersey.

When the start button 97 is operated to close the circut to the motor to start the machine, as above set forth, the timer 102 is adjusted, for the predetermined time interval necessary to accelerate the machine from Zero to 900 c.p.m., to close the circuit through the coil 107 to operate the solenoid 62 to turn the lever 52 and shift the center of oscillation of the levers 25 at or slightly before the machine reaches 900 c.p.m. The timer 102 then maintains the circuit through the coil 107 energized as the machine continues to accelerate to its maximum speed. When the circuit to the motor is opened by operating the stop button 85 to stop the machine, the circuit through the timer 102 and solenoid 62 is also opened and at this time the lever 52 is moved clockwise to its stopped position with the set screw 51 against the bracket 53 by the spring 55 to shift the shaft 28 and eccentric portions 50 to their initial position.

It is to be understood that the angular dimensions above set forth in connection with the initial position b and the adjusted position c of the portions 58 on shaft 28 are for illustrative purposes only and may be varied to obtain the desired results, the position b being variable through the set screw 51, and the position c being variable through the adjustable link 60. Also where reference is made to a timer device for controlling the operation of the circuit to energize the solenoid 62 as hereinbefore set forth other types of control devices may be employed for this purpose such as a centrifugal switch which may be operated from one of the operating shafts of the machine or a proximity type switch which is controlled directly from the presser member when the latter reaches the acceptable limit of its overtravel.

A further advantage of a machine incorporating the instant invention lies in the ease of adjustment of the press bar relative to the needle bar when such adjustment is required to accommodate the machine to knit yarns of differing characteristics. Normally in the prior machines any such change required the adjustment of all of the several links 30, there conventionally being nine of these on the machine. With the present invention these links need only be initially adjusted to assure parallelism of the presser and needle bars and thereafter, to accommodate the machine to different yarns, all that is necessary is to adjust screw 51 thus greatly saving in down time.

It will be understood that the improvements specifically shown and described, by which the above results are obtained, can be changed and modified in various ways without departing from the invention herein disclosed and hereinafter claimed.

What is claimed is:

1. In a warp knitting machine having spring bearded needles adapted for operation through stitch forming movements, a presser member, and means for operating said presser member to close the beards of said needles during said stitch forming movements of said needles including a first lever on which said presser member is supported, a first shaft, an eccentric portion on said first shaft on which said first lever is pivotally supported, a second lever, a second shaft on which said second lever is pivotal- 1y supported, a first link pivotally connecting said first and second levers, a third lever, a drive shaft, a motor for rotating said drive shaft, eccentric means on said shaft for operating said third lever, a fourth lever pivotally con nected to the free end of said third lever, a fourth shaft on which said fourth lever is pivotally supported, a second link, said second link having one end pivotally connected to said second lever intermediate said second shaft and the connection with said first link and said second link having its other end pivotally connected to said third lever intermediate said drive shaft and said free end thereof, a first means for oscillating said first shaft to move said eccentric portion to a first position when said machine is stopped and a second means for oscillating said first shaft to move said eccentric portion to a second position during operation of said machine.

2. In a machine according to claim 1 in which said first means for oscillating said first shaft includes an arm secured to said shaft, and means for moving said arm in one direction to move said eccentric portion to said first position, and there is means for stopping said arm when said accentric portion is in said first position.

3. In a machine according to claim 2 in which said second means for oscillating said first shaft includes said arm, and means for moving said arm in a direction opposite to said one direction.

4. In a machine according to claim 3 in which said means for moving said arm in said opposite direction comprises a solenoid, and an electrical circuit for operating said solenoid.

5. In a warp knitting machine having spring bearded needles adapted to be operated through stitch drawing movements, a presser member, a shaft, eccentric means on said shaft for supporting said presser member for movement to close the beards of said needles during said stitch drawing movements thereof, a first means for rotating said shaft to move said eccentric means to a first position to cause said presser member to move along a first path during said beard closing movements thereof, a second means for rotating said shaft to move said eccentric means to a second position to cause said presser member to move along a second path during said closing movements thereof, and means for moving said presser member along said first and second paths.

6. In a warp knitting machine having spring bearded needles adapted to be operated through stitch drawing movements, a presser member, a lever on. which said presser member is supported, a shaft, eccentric means on said shaft for supporting said lever for operation to move said presser member to close the beards of said needles during said stitch drawing movements thereof, a first means for moving said shaft and said eccentric means thereon to a first position to cause said lever during operation to move said presser member along a first path during said beard closing movements thereof, a second means for moving said shaft and said eccentric means thereon to a second position to cause said lever during operation to move said presser member along a second path during said beard closing movements thereof, and means for operating said lever to move said presser member along said first and second paths.

7. A machine according to claim 6 in which there is means for controlling the operation of said first and second means to move said eccentric means to said first and second positions.

8. A machine according to claim 7 in which there is means for operating said machine, and said means for controlling the operation of said first and second means is controlled by said operating means for said machine.

References Cited UNITED STATES PATENTS 2,143,609 1/1939 Morton et al 66--86 2,943,468 7/1960 Wollett et al 66--86 2,948,998 5/1961 Liebrandt et a1 66-86 ROBERT R. MACKEY, Primary Examiner.

Claims

5. IN A WARP KNITING MACHINE HAVING SPRING BEARDED NEEDLES ADAPTED TO BE OPERATED THROUGH STITCH DRAWING MOVEMENTS, A PRESSER MEMBER, A SHAFT, ECCENTRIC MEANS ON SAID SHAFT FOR SUPPORTING SAID PRESSER MEMBER FOR MOVEMENT TO CLOSE THE BEARDS OF SAID NEEDLES DURING SAID STITCH DRAWING MOVEMENTS THEREOF, A FIRST MEANS FOR ROTATING SAID SHAFT TO MOVE SAID ECCENTRIC MEANS TO A FIRST POSITION TO CAUSE SAID PRESSER MEMBER TO MOVE ALONG A FIRST PATH DURING SAID BEARD CLOSING MOVEMENTS THEREOF, A SECOND MEANS FOR ROTATING SAID SHAFT TO MOVE SAID ECCENTRIC MEANS TO A SECOND POSITION TO CAUSE SAID PRESSER MEMBER TO MOVE ALONG A SECOND PATH DURING SAID CLOSING MOVEMENTS THEREOF, AND MEANS FOR MOVING SAID PRESSER MEMBER ALONG SAID FIRST AND SECOND PATHS.