GB2151663A - Needle control in a knitting machine - Google Patents

Abstract

A knitting machine such as a flat machine comprises knitting needles (2) driven according to pattern by rockers (5) fastened to slides (6) the rockers having a crank drive (10) and selectively transmitting the motion to the needles according to the positions of the slides (6) each of which has a foot (22) movable in a guide path formed from movable and non-movable guide elements (23). To enable individual needle selection, each slide (6) is also provided with a back foot (25) which is engageable with a foot (14) of a respective arm (12) pivotable about an axis (17) and supported by a spring-loaded bolt (18). Arranged above the shank (15) of the arm is a camshaft (26) which is operable synchronously with the rockers (5) and carries cams (27) to pivot the arms (12). Arranged behind the shank (15) of each arm (12) is a leaf spring (28) controllable by one of the cams (27) and by magnets (30, 31) to selectably retain the arm (12) in a position in which its foot (14) is clear of the back foot (25) of the arm. <IMAGE>

Description

SPECIFICATION Needle control in a knitting machine The present invention relates to a knitting machine and has particular reference to needle control, in dependence on pattern, in a flat knitting machine.

In DE-OS 3238065 there is disclosed a pattern device in a knitting machine in which the actuation of the knitting needles according to pattern takes place through rockers fastened to slides. Each slide is provided with a foot, which is guided in a path formed by guide elements. The guide elements comprise a continuous rail and movable slide pieces. Together the slide pieces give the width of a knitting system. These slide pieces can be brought, corresponding to the desired needle movement, out of action. If all slide pieces are depressed, the feet of the slides are not held, the rockers cannot transfer movement to the needles and the threads form a float. If all slide pieces are disposed in action, the associated needle forms a stitch. If only one of the slide pieces is depressed, the associated needle forms a catching loop.

However, this needle actuation according to pattern only allows group selection of needles for formation of stitches, loops and floats, but not the selection of the individual needles in a row.

There is therefore scope for widening of the pattern possibilities, especially to enable production of knitting which requires individual needle selection.

According to the present invention there is provided a knitting machine comprising a plurality of knitting needles, a plurality of rockers each cyclically operable to effect axial displacement of a respective one of the needles, a plurality of slides each pivotably connected to a respective one of the rockers to define the rocker fulcrum, first locking means co-operable with first detent means of the slides to lock the slides against sliding movement and second locking means co-operable with second detent means of the slides to lock selectable ones of the slides against sliding movement, the second locking means comprising a plurality of pivotable arms each resiliently biassed into locking engagement with the second detent means of a respective one of the slides, a respective cam operable synchronously with each rockerto pivot the associated arm out of such locking engagement and a respective catch selectably actuable to retain each arm out of locking engagement.

In a preferred embodiment, the first detent means of each slide comprises a first projection or middle foot co-operable with moveable and non-movable abutment elements and the second detent means of each slide comprises a second projection or rear foot engageable in a recess in the associated arm, the arm being resiliently supported by a spring bolt.

Above the arms is a camshaft, drivable synchronously with crank drive means for the rockers, carrying the cams and behind each arm is a resilient element or leaf spring actuable by one of the cams and an electromagnet.

Preferably, the cams from needle division to needle division are offset relative to each other on the camshaft about an angle corresponding to the angle, present from needle division to needle division, of eccentric drive bolts of the crank drive means. The resilient element may be provided with a nose for the retention of the associated arm of the rocker in the disengaged setting. The resilient elements are preferably arranged to be pressable by the cams into the action range of the electromagnets.

An embodiment of the present invention will now be more particularly described by way of example with reference to the accompanying drawing, the single figure of which is a schematic sectional side view of needle displacement control means in a flat knitting machine embodying the invention.

Referring now to the drawing, there is shown part of a knitting machine comprising a plurality of knitting needles 2 each axially displaceable by a respective rocker 5 which is cyclically operable by an associated slide 7. The slide 7 has arms retained in slide blocks and is slidable by an eccentric pin on a crank disc 10, the disc being supported and driven by shafts. In order to provide needle movement according to pattern in a full drive setting, a loop setting or a non-working setting, a slide 6 with a foot 22 is pivotably connected to each rocker 5 at the fulcrum 8 thereof, the slide 6 being arranged in a slide bed 19 and guided in a path formed by movable guide elements 23. Each slide 6 is also provided with a rear foot 25, which engages in a Ushaped foot 14 of an associated pivot arm 12, the arm being mounted at one end thereof in a bed 16 to be pivotable about an axis 17.The shank 15, behind the foot 14, of the arm 12 is supported on a springloaded bolt 18.

Disposed above the shanks 15 is a camshaft 26 with cams 27 which are offset relative to each other and which are each associated with a respective one of the arms 12. The angle of offset corresponds to the angle of the eccentric bolts, arranged at the discs 10, from needle division to needle division.

The camshaft 26 is driven synchronously with the discs 10, i.e. it executes a full rotation per stitch forming operation, but with a course required for the individual needle selection. The end of each shank 15 co-operates with a spring bar 28 which is provided with a nose 29 and is fastened at one end.

The spring bar 28 is held by a rapidly reversible electromagnet 30 as well as two further magnets 31.

The magnets 31 are permanent magnets and serve to strengthen the force of the magnet 30.

To secure the non-working setting of the knitting needles 2 when oscillations, etc., occur, a respective peg 33 is resiliently mounted in the bed 16 and limits the movement of a back foot of each needle 2 and thus the movement thereof when the associated arm 12 is downwardly pressed.

On stitch forming without individual needle selection, for example for the production of a patent orfishermen's stitch edge at the knitting start, the needle selection takes place solely through the movable guide elements 23, in that these free the foot 22 entirely, partly or not at all. Each arm 12 is, with each rotation of the camshaft 26, pressed downwardly against the force of the spring-loaded bolt 18 by the associated cam 27 and is held in this setting by the nose 29 of the associated spring bar 28 freed by the magnets 30 and 31 (dotted representation of the arm 12 and spring bar 28).

Thus the foot 25 of the slide 6 is disposed outside the range of engagement of the foot 14 of the arm 12.

Equally, for the production of Jacquard knitting with individual needle selection, the arm 17 is downwardly pressed by the cam 27 with each rotation of the camshaft 26 and, depending on the state of the magnet 30 (energised or de-energised), is either held in this setting by the nose 29 of the spring bar 28 or pressed back upwards by the force of the spring-loaded bolt 18. If the selection of the knitting needles 2 according to pattern is to provide the formation of stitches or loops, then the spring bar 28 is held by the magnets 30 and 31 and the arm 12 returns to its basic setting in which the foot 25 of the slide 6 engages in the foot 14 of the arm. Thus, the foot 2 of the slide 6 is either held fast or partly freed corresponding to the setting of the guide elements 23. The knitting needle 2 forms a stitch or a loop.

Forthe production of a float, i.e. for non-operation of the needle 2, the magnets 30 and 31 free the spring bar 28, the nose 29 of which holds the shank 15 of the arm 12 in its lower setting against the force of the spring-loaded bolt 18. The guide elements 23 are depressed and the needle 2 remains in its rest setting. Subsequently, on further rotation of the cam 27, the spring bar 28 is again pressed against the magnets 30 and 31 and, according to the desired needle selection, is either held by these or freed again.

Claims (10)

1. A knitting machine comprising a plurality of knitting needles, a plurality of rockers each cyclically operable to effect axial displacement of a respective one of the needles, a plurality of slides each pivotably connected to a respective one of the rockers to define the rocker fulcrum, first locking means co-operable with first detent means of the slides to lock the slides against sliding movement and second locking means co-operable with second detent means of the slides to lock selectable ones of the slides against sliding movement, the second locking means comprising a plurality of pivotable arms each resiliently biassed into locking engagement with the second detent means of a respective one of the slides, a respective cam operable synchronously with each rocker to pivot the associated arm out of such locking engagement and a respective catch selectably actuable to retain each arm out of locking engagement.

2. A knitting machine as claimed in claim 1, the first locking means comprising movable and nonmovable abutment elements.

3. A knitting machine as claimed in either claim 1 or claim 2, the second detent means of each of the slides comprising a projection engageable in a recess of the associated one of the arms.

4. A knitting machine as claimed in any one of the preceding claims, wherein the cams are carried on a camshaft arranged above the arms.

5. A knitting machine as claimed in claim 4, comprising a plurality ofangularly spaced eccentrics to provide phase-displaced cyclic operation of the rockers, the cams being correspondingly angularly spaced around the camshaft to provide correspondingly phasedisplaced cyclic movement of the arms.

6. A knitting machine as claimed in any one of the preceding claims, wherein each of the catches comprises a resilient element biassed into a setting for retention of the associated arm.

7. A knitting machine as claimed in claim 6, wherein each of the resilient elements is provided with a retaining nose engageable with an end portion of the associated arm.

8. A knitting machine as claimed in either claim 6 or claim 7, comprising a respective electromagnet selectably energisable to hold each resilient element in a setting clear of the associated arm.

9. A knitting machine as claimed in claim 8, wherein each of the resilient elements is arranged to be movable by the associated cam into the attractive range of the associated electromagnet.

10. A knitting machine substantially as hereinbefore described with reference to the accompanying drawing.