GB2065729A - Improvements in or relating to stitching machines - Google Patents

Abstract

An assembly is disclosed for use in changing a lock stitch machine to a chain stitch machine or for inclusion in a new chain stitch machine and comprising a rod 17 which can be axially reciprocated by motor 14 through drive coupling 26, 28, 30 and eccentric 32. The rod 17 can be rotated by eccentric 20 connected to shaft 15 driven by motor 14. The rod is fixed to parallel bars 37, 38 which slidably support cross bars 39 carrying loopers 40. Needles 51 cooperate with the loopers 40 to stitch material passing between pressure plates 52. <IMAGE>

Description

SPECIFICATION Improvements in or relating to stitching machines This invention relates to stitching machines.

It is known to make quilting, for example as used in anoraks or eiderdowns, having two outer fabric layers between which is sandwiched, for example, a layer of non-woven material, the layers being stitched together. The stitches are inserted by machine and it is known to use machines which insert lock stitches and machines which insert chain stitches. The speed of operation of the chain stitch machines, and thus the production of quilting using these machines, considerably exceeds that of the lock stitch machines; however, present chain stitch machines are expensive.

According to this invention an assembly for driving loopers in a chain stitch machine comprises elongate looper support means mounted for rotation about an axis and for axial sliding movement, means for oscillating the support means about the axis, and means for axially reciprocating the support means.

The invention also includes a chain stitch machine having such an assembly.

The invention may be performed in various ways and one specific embodiment with possible modifications will now be described by way of example with reference to the accompanying somewhat diagrammatic drawing, which is a perspective front view of a chain stitch quilting maching according to the invention including a looper drive assembly according to the invention.

The chain stitch machine has a frame 10 on legs 11, the frame including spaced uprights 12, 1 3. An electric motor 14 with suitable controls (not shown) drives a horizontal rotary shaft 1 5 rotatable in bearings in supports 1 6. A horizontal circular section rod 1 7 is slidably and rotatably carried in bearings 1 8 in three spaced supports 1 9 detachably secured on the frame 10. The shaft 1 5 carries an eccentric 20 to which is pivoted at 21 about a horizontal axis a link 22 whose other end if pivoted at 23 to an extension 24 of rod 17. As shaft 1 5 rotates, the rod 1 7 is rotatably oscillated.

The shaft 1 5 carries a gear wheel 25 which drives a chain 26 which in turn drives gear 27 carried on shaft 28 rotatable in upright 1 3. The other end of shaft 27 carries a right angle drive device 29 which drives a vertical output shaft 30 carried in bearings 31 on upright 13 and at its lower end carrying a horizontal eccentric 32 pivoted at 33 to one end of a horizontal link 34 pivoted at its other end 35 to the end of the rod 1 7. Thus, as the shaft 30 rotates, the rod 1 7 slides axially to and fro in the supports 1 9.

Spaced upwardly diverging rods 36 fixedly connect the rod 1 7 to two spaced horizontal square section bars 37, 38 parallel to rod 17 and having coplanar flat upper surfaces and carrying a plurality (only one shown) of parallel bars 39. The bars 39 are at right angles to rod 17 and each carries two spaced loopers 40 of known construction. Each looper 40 has a vertical shank which is detachably received in a bore in the bar 39 and a forwardly extending portion carrying the looper thread. Thus as shaft 1 5 rotates, the loopers move to and fro at right angles to rod 1 7 (as indicated by arrows B) - with a slight up and down movement also; and as shaft 30 rotates the loopers 40 move to and fro with the rod 17 as shown by arrows A.

Diagrammatically shown at 50 is a known mounting and control mechanism for a plurality of vertical needles 51 (only two shown) respectively cooperating with the loopers 40. Two vertically spaced flat horizontal pressure plates 52 each have a plurality of aligned holes through which the needles 51 pass in operation. The material to be stitched is fed rearwardly through the machine between the plates 52, the loopers 40 being beneath the lower plate 52. The plates 52 are carried on suitable fixed mountings which may be connected to the uprights.

Means are provided for moving the material sideways.

The remainder of the machine is generally of construction similar to an existing lock stitch machine and need not be described in detail but includes, as will be known to the skilled man, a plurality of axially spaced bobbins (only one shown at 60) respectively feeding yarn 61 through tensioning devices 62 and thread take-up devices to selected ones of the loopers 40. Similarly the needles, as selected, are supplied with thread from suitable bobbin supplies. The machine also includes the usual mechanical connections for coordinating the movements of the needles and shafts 16, 30.

The assembly of supports 19, rod 17, bars 37, 38, eccentrics and links can be supplied as a unit, or as a kit of parts, and can readily be used to modify a known lock stitch machine to a chain stitch machine, with appropriate removal of parts from the lock stitch machine.

Preferably the looper bars 39 are slidably mounted in guideways 70 carried on bars 37, 38 so that the looper bars 39 can be withdrawn and replaced by an operator for re-threading or replacement.

In a modification, the coupling 35 is connected to the mid point of a bar connecting the ends of bars 37, 38 rather than to the rod 17.

The assembly provides a simple and relatively inexpensive means of driving the loopers.

The general movements of the needles and loopers to form chain stitching are known.

Described generally, considering an initial position with the needle up and the looper forwards and to the left of the needle as viewed from the front, with the needle thread round the looper, the needle moves down, the looper moves to the right of the needle and rearwards, the needle passing the looper slightly rearwards of the looper point and passes through the loop formed by the looper thread; the looper completes the rearwards movement and the needle complete the downward movement. The needle starts to rise back to the initial position, the looper moves to the left of the needle and forwards, passing through the loop formed by the needle thread.

Claims (10)

1. An assembly for driving loopers in a chain stitch machine comprising elongate looper support means mounted for rotation about an axis and for axial sliding movement, means for oscillating the support means about the axis, and means for axially reciprocating the support means.

2. An assembly as claimed in Claim 1, in which the means for oscillating comprises an eccentric pivotally connected to the support means.

3. An assembly as claimed in Claim 1 or Claim 2, in which the means for axially reciprocating comprises an eccentric pivotally connected to the support means.

4. An assembly as claimed in Claim 3, comprising a motor coupled to rotate the eccentrics, the coupling including a shaft connected to drive one of the eccentrics, and connected to drive the other eccentric through a right angle drive device.

5. An assembly as claimed in any preceding claim, in which the looper support means comprises a rod rotatably and slidably mounted and carrying two spaced parallel bars on which the loopers are mounted.

6. An assembly as claimed in Claim 5, in which the loopers are carried on supports detachably connected to the bars.

7. An assembly as claimed in Claim 6, in which the loopers are mounted in elements slidably connected or convertible to the bars.

8. An assembly for driving loopers substantially as hereinbefore described with reference to and as shown in Fig. 1 of the accompanying drawings.

9. A chain stitch machine including a looper drive assembly as claimed in any preceding claim.

10. A kit of parts for forming a looper drive assembly as claimed in Claim 5 and comprising a rod, supports including bearings in which the rod can be slidably and rotatably mounted, the rod carrying spaced bars having guides for slidably receiving elongate supports for carrying the loopers, links and eccentrics for connection to rotary shafts for driving the rod.