ACTUATORS FOR ELECTRONIC SELECTION IN KNITTING MACHINES

Abstract: According to the invention there is provided (Figure 2) an actuator for electronic selection in knitting machines having a plurality of solenoids (2) and associated rockers (24) each having rear projections (28), for cooperating with an armature (6), of a coil (16) of the associated solenoid (2) and front projections (32) for cooperating with pattern butts, in which the rockers (24) each have (1) a body of a plastics material with an axially extending cylindrical part arranged adjacent and parallel to the bodies of other rockers and a rear projection (28) which is arranged at different positions along the length of the different cylindrical parts and engages the armature (6) of the associated solenoid (2), the armature (6) moving in the same plane or in parallel planes, and (11) a metal member (34) secured to front projections (32) of the rocker bodies to engage the pattern butts.

Description: TITLE: Actuators for electronic selection in knitting machines DESCRIPTION Field of invention The invention relates to actuators for electronic selection in knitting machines such as for example V-bed flat or circular knitting machines. Background of invention Actuators may have a plurality of solenoids with associated rockers with projecting front ends for engaging pattern butts on jacks in tricks of a needle bed. The actuators are fixed with respect to the cam system and are operated at high frequenices during knitting when the actuators and jacks move at high relative speeds. A form of actuator is known on certain types of V-bed machines using monostable solenoids incorporating a coil and permanent magnet made by a West-German company Harting. Six rockers are mounted, spaced from one another with parallel rocking axes. The _ Λn .-, " V IPO - rockers are of metal and have at the rear extensions with a recess for gripping an end of a pivotable armature mounted inside the coil.. The solenoids are arranged in a T-shaped configuration when seen fron above. The armature ends converge to reception places inside the respective extensions of the rockers, which extensions lie substantially in one line. The individual rockers are spaced to permit their Q movement in opposite senses when required. It is .an object of the invention to provide a different actuator having superior performance characteristics * . A difficulty is the dynamic behaviour 5 and irregularities therein occurring at high knitting speeds or after prolonged use of the actuators. Summary of invention These problems can be significantly o reduced by the simple expedient of forming the body of the rockers from a plastics material with an axially extending cylindrical part which is arranged close to and parallel to other cylindrical parts of other rockers and has a rear 5 extension for cooperating with a solenoid at a desired position along its length so that all the armatures operate in the same plane or in parallel planes, the pattern butts being operated through a metal insert in the body at the front 0 of the sleeve. It is believed that the good dynamic behaviour over long periods is due to the reduced even wear at the joint of the rocker body and armature, the restriction of ingress of dirt into the solenoids by the wall formed 5 by successive sleeve bodies and the confinement of the magnetic field by the plastics material of which the sleeve bodies are formed. In preferred forms of the invention the rockers move through a dead centre position and have their movement limited by parts of the solenoid. Drawings Figure 1 shows a rear view of an actuator according to the invention with a lid removed; Figure 2 shows a section along line II-II in Figure 1; Figure 3 shows a side view of an individual Harting solenoid used in the actuator of Figure 1; and Figure 4 shows a section along line IV-IV ±n Figure 1. Specific * description With reference to the Figures, six Harting solenoids.2 are arranged side**-by-side but vertically off-^set so as to place the pivot axes 4 of the armatures 6 at six equally spaced levels. The solenoids 2 have (see Figure 3) an outer bracket 8 with screw holes 10 for mounting the solenoids 2 on a plate 12, and inner brackets 14 mounting a coil 16. At the top there is a permanent magnet 18. The travel of the movable end of the armatures 6 is limited by in urned edges of the brackets 14. Control pulses are supplied to the coils 16 by a cable introduced through a hole in a lid 20. The lid 20 and the plate 12 with its solenoids 2 are screwed to the top of a housing 22. At the front a number of rocker shafts 23 are retained in extensions 26 on the front of the housing 22 t Rockers 24 are of a plastics material and comprise rear lever extensions 28 with recesses for receiving ends of the armatures 6, These .extensions 28 are 5 spaced sideways as can be seen in Figure 4 and are on a sleeve 30 surrounding the shafts 24, The sleeve 30 lies against a plastics bush 31 which holds the sleeve 30 in the desired position between the extensions 26. The sleeves 30 j n and bushes 31 are closely adjacent so as to substantially protect the solenoids 2 in the inside of the housing 22 from the surroundings of the housing 22. The rockers 24 also have front extensions 32 with a wear resistant metal 1_ member 34 moulded into the extensions 30 at the front. Because of the-combination of the sleeves 30 and bushes 31 along the rockers shafts 23, one size of bush 31 and two mouldings for the rockers 32, provide all the variations in 2o rear extension position necessary for a six-high actuator. In operation when it is desired that a pattern butt on a jack (not shown) be engaged, an electrical pulse is passed through the appropriate 25 coil 16 causing the armature 6 to move away from its normal position (as shown in Figure 2 for the fourth rocker 24 from above) to its active position (as shown in Figure 2 for the second rocker 24 from above). Consequently 30 the armature 6 moves through a small angle and the associated rocker 24 through a larger angle. When the pattern butts meet the metal member 34 of the moved rocker 24 it is pushed into the trick from an outward position at A (Figure 4) 35 to an inward position at B. The reaction • -•. - force on the rocker is absorbed by the armature 6 bearing against the inturned edge of the lower bracket 14. The end of the armature 6 passes through a line interconnecting 5 the rocker and armature pivot axis (i.e. through dead-centre) . The reaction force thus cannot lead to a dislodging of the rocker and armature. The actuators are compact. The space ^0 between adjacent extensions 32 and bushes 31 is small. As seen in Figure 1, two or more actuators can be mounted closely adjacent oh a cam carriage 36. Each armature 8 is connected to its rocker 24 in an identical. • ^5 manner so that the dynamic behaviour of the different rockers 24 is* very similar. Each armature 6 is subject to the same sort of low friction with respect to ' its rocker 24. The rockers and armatures wear in the same 20 manner and continue to perform similarly af er prolonged use of the actuators. The actuators operate with only very light movable masses: the armature which is of metal but moves through a small angle and a rocker which 25 is of ligh plastics material and moves through a larger angle. The magnetic fields generated by the coils are shielded off from the front of the rockers, the jacks and the needle bed by the plastics sleeves 30 and the bushes 31. The 30 inlaid metal member 34 is thus not magnetised and the collection of metal dust on operating parts outside the housing 22 is reduced. Ingress of dirt into the housing 22 is equally obstructed by the sleeves 30 and bushes 31. 35 Because of the efficient magnetic insulation O PI of the actuator m-3, -function as a result of induced magnetism on operation parts of the knitting machine are avoide , The actuator is efficient at high cam system speeds. O A. WI

Claims: ■*■* . 7 - CLAIMS * 1. Actuator for electronic selection in knitting machines hsving a plurality of solenoids and associated rockers each haying ' rear projections for cooperating with an armature of a coil of the associated solenoid and front projections for cooperating with pattern butts, in which the rockers each have (I) a body of a plastics material with an axially extending cylindrical part arranged adjacent and parallel to the bodies of other rockers and a rear projection which is arranged at different. positions * along the length of the different cylindrical parts and engages the armature of the associated solenoid, the armatures moving in the same plane or in parallel planes, and (II) a metal member secured to front projections of the rocker bodies to engage the pattern butts. 2. Actuator according to claim 1 in which the cylindrical parts of the rockers are hollow and mounted on a shaft, the rocker being axially located on the shaft by bushes of plastics material. 3. Actuator according to claim 1 or claim 2 in which the armatures are pivotable on an axis at the rear of the coil and the armature and rear projection pass through a line interconnecting the armature and rocker pivot axis on moving from an active to an inactive rocker position and the extent of armature movement is limited by abutments. 4. Actuator according to claim 3 in which the said line is normal with respect to tricks in a needle bed. 5. Actuator according to any of the preceding claims in which the armatures have a plastics portion at their ends for engaging in a recess in the rear projections. 6. Actuator for electronic selection substantially as described with reference to the drawings. O PI

Inventors: TRAUTNER J
Applicants: BENTLEY ALEMANNIA LTD, TRAUTNER J
Application year: 1980
Main classification: D04B15
IPC codes: D04B15