US3807331A

US3807331A - Sewing machines

Info

Publication number: US3807331A
Application number: US00308848A
Authority: US
Inventors: W Simpson
Original assignee: Newey Goodman Ltd
Current assignee: Newey Goodman Ltd
Priority date: 1972-11-22
Filing date: 1972-11-22
Publication date: 1974-04-30
Anticipated expiration: 1991-04-30

Abstract

In a lock-stitch sewing machine having a needle carrier for at least two needles, the bobbins are arranged with their axes upright, one in front of one needle and the other behind the other needle. The bobbin mountings are such that they can be moved away from the sewing station and needle carrier so that empty bobbins can be replaced by full ones without the work being disturbed. The sewing machine may be of the swing-needle kind in which case the swinging movement of the needles is substantially tangential to the bobbins. The drive to the looping mechanisms co-axial with the bobbins may remain engaged when the bobbin mountings are moved so that the synchronisation of the looping mechanisms is not disturbed.

Description

Simpson SEWING MACHINES William Leslie Simpson, Birmingham, England [73] Assignee: Newey Goodman Limited,

Birmingham, England 22 Filed: Nov. 22, 1972 21 Appl. No; 308,8

[75] Inventor:

[52] US. Cl ..112/186, 112/106, 112/158 R, 112/163, 112/193 [51] Int. Cl D05b 3/18 [58] Field of Search 112/2, 104, 105,106,111, 112/158 R, l63,167,168,180,181,182, 184,186,191,193, 211, 214

[451 Apr. 30,1974

1,413,274 4/1922 HOrat 112/184 1,574,122 2/1926 Sharaf 1 1 112/163 3,602,167 8/1971 Papajewski 112/184 In a lock-stitch sewing machine having a needle carrier for at least two needles, the bobbins are arranged with their axes upright, one in front of one needle and the other behind the other needle. The bobbin mountings are such that they can be moved away from the sewing station and needle carrier so that empty bobbins can be replaced by full ones without the work being disturbed. The sewing machine may be of the swing-needle kind in which case the swinging movement of the needles is substantially tangential to the bobbins. The drive to the looping mechanisms co-axial with the bobbins may remain engaged when the bobbin mountings are moved so that the synchronisation of the looping mechanisms is not disturbed.

10 Claims, 17 Drawing Figures agam'rgam PATENTEDAPRSO m4 sum 01 or 12 fOE PATENTEDAPR so 1914 swan 03 0F 12 slaomsl PATENTEDAPR 30 1974 saw us or 12 PATENTEDAPMQ m4 sum o7 0F 12 PATENTED APR 30 m4 sum 08 HF 12 FATENTEMPR 30 m4 3.80 1331 sum us (If 12 PATENTED APR 3 0 I974 sum 10 HF 12 PATENTEDAPR 30 m4 sum 11m 12 SEWING MACHINES This invention relates to lock-stitch sewing machine assemblies of the kind including feed means for feeding work through a sewing station, a reciprocable needle carrier adapted to carry at least two needles disposed side by side in a plane transverse to the direction of work feed, means for reciprocating the needle carrier so that the needles move lengthwise in that plane, and bobbin mountings and drive means for looping mechanisms associated with respective needles.

Sewing machines of that kind are capable of forming two or more parallel lines of lock-stitches. Where such machines are used for producing lines of stitches of indefinite length, as in the production of tapes to which hooks, eyes or other fastenings are secured, difficulties arise in practice due to the bobbins running out of thread at relatively frequent intervals and having to be replaced with newly charged bobbins. Although various proposals have been made which enable a warning to be given just before the thread on a bobbin runs out this does not alter the fact that the physical problem of removing or replacing the bobbins is often awkward, particularly when attachments are secured to the bed of the machine above the place where the bobbins are mounted and when work of a complex type overlies these places.

An object of the present invention is to avoid or reduce these difficulties while at the same time affording other advantages, the nature of which are outlined be low.

According to the present invention there is provided a lock-stitch sewing machine assembly of the kind including feed means for feeding work through a sewing station, a reciprocable needle carrier adapted to carry first and second needles disposed side by side in a plane transverse to the directions of work feed, means for reciprocating the needle carrier so that the needles move lengthwise in that plane, first and second bobbin mountings and first and second drive means for looping mechanisms, associated respectively with the first and second neddles, and defining first and second bobbin axes, the assembly being characterised in that the bobbin axes are at least substantially parallel with the nee dles, the first bobbin axis being substantially directly to the rear of the first needle and the second bobbin axis being substantially directly in front of the second needle, as considered in the direction of work feed through the sewing station, and the bobbin mountings are movable away from the work station and the needle carrier to enable empty bobbins to be replaced by full ones.

It must be understood that the terms in front of and to the rear of as used in the last preceding paragraph relate to directions parallel with the direction of movement of the work through the machine at the point where the stitches are formed and transverse to the common plane through the axes of the two said needles.

This arrangement of the bobbin mountings has a number of advantages. Firstly it is possible to replace empty bobbins by full ones without disturbing sewing attachments or work on the bed of the machine. Secondly this arrangement imposes almost no restriction on the spacing between the two needles, for one bobbin mounting together with its associated parts lies almost entirely to the rear of the transverse plane containing the axes of the needles, while the other bobbin mounting together with its associated parts lies almost entirely in front of that plane; this being so, very little lateral offset between the bobbin mountings is required. Thirdly it is possible to use this arrangement in a machine assembly of the kind in which the needle carrier is movable transversely, as in a so-called swing-needle machine, as the transverse movement of each needle is at least substantially tangential to the associated bobbin so that the bobbin and looping mechanism can continue to operate satisfactorily even though the position of the needle may shift slightly around the periphery of the bobbin.

The bobbin mountings may be arranged to be moved in any suitable direction to enable the empty bobbins to be replaced, but preferably the bobbin carriers are mounted for pivotal movement about a common transverse axis to the rear of the sewing station, so that they can be accessible to an operator in front of the machine. Alternatively the bobbins may be replaced by automatic means.

Although the invention is primarily applicable to machines with only two needles it is also applicable to machines with three or more needles, the bobbin mountings for successive needles preferably being disposed so that they are adapted to carry their associated bobbins for rotation about axes which are alternately in front of and to the rear of the positions of the associated needles. Clearly the bobbin mountings for alternate needles are side by side so that there is a restriction on the minimum possible spacing between those alternate needles. Nevertheless this is the only additional restriction imposed by this arrangement as compared with the arrangement for two needles alone.

One particular form of sewing machine assembly embodying the present invention will now be more particularly described with reference to the accompanying drawings, in which:

FIG. 1 is a plan view of the sewing machine assembly,

FIG. 2 is a side view of the assembly, as viewed from the left of FIG. 1 but to a rather smaller scale,

FIG. 3 is a plan view, to a larger scale, of the bed of the sewing machine, parts being broken away to reveal the interior,

FIG. 4 is a section along the line 44 of FIG. 3.

FIG. 5 is a section along the lines 5-5 of FIG. 3,

FIG. 6 is a section along the line 66 of FIG. 3,

FIG. 7 is a front view, to a larger scale, of the tape feed mechanism,

FIG. 8 is an end view of the mechanism shown in FIG. 7, as viewed from the right of FIG. 7,

FIG. 9 is an end view of the mechanism shown in FIG. 7, as viewed from the left of FIG. 7,

FIG. 10 is a section, to a larger scale, along the line l010 of-FIG. 1,

FIG. 11 is a rear elevation of the assembly shown in FIGS. 1 and 2,

FIG. 12 is a somewhat diagrammatic front elevation of the sewing machine, illustrating the mechanism for causing the needle carrier to swing from side to side,

FIG. 13 is a rear elevation, to a larger scale, of mechanism on the sewing machine,

FIG. 14 is a diagrammatic section through eye tape produced by the assembly,

FIG. 15 is a plan view of the eye tape,

FIG. 16 is a view, to a larger scale, of one of the eyes,

and

FIG. 17 is a plan view of the mechanism for inserting the eyes into the tape.

In many of these FIGURES parts are broken away to reveal parts which would otherwise be hidden. Further, many of the FIGURES show only portions of the assembly, the parts behind the portions illustrated usually being omitted for clarity of illustration.

The assembly illustrated is adapted to sew preformed metal eyes to tape so as to form eye-tape of the kind described below with reference to FIGS. 14 to 16.

In the following description the assembly is described as if it were in the position normally adopted in use, and from the point of view of an operator standing in front of the assembly. As will become apparent the assembly incorporates a sewing machine which forms stitches on tape, the tape moving from the front of the sewing machine to the back thereof. The sewing machine 1 is of generally conventional construction (as best seen in FIGS. 1, 2 and 12) which includes an upstanding pillar 2 with an arm 3 extending to the left from the top of the pillar and carrying at its left-hand end a vertically reciprocable needle carrier 4. The machine is designed to use two needles and 6, mounted side by side on the needle carrier 4 and usually spaced apart some five eighths or three quarters of an inch. The machine includes mechanism described below with reference to FIG. 12 enabling the needle carrier 4 to swing sideways, the extent of the swing being typically three thirty seconds of an inch. The machine is also provided with thread guides and tensioners and associated parts of conventional construction which are not illustrated and will not be further described.

The bed 7 of the machine 1, below the needle carrier 4, is not provided with feed dogs, the eye-tape being moved forward by another form of feed mechanism as described below with reference to FIGS. 7 to 9. Two laterally extending slots (not shown) are formed in the bed of the machine to receive the

needles

5 and 6. Bobbins, and looping mechanisms are disposed below the bed 7 of the machine. These are of generally conventional construction and are therefore not illustrated. When the machine is in use each of the

needles

5 and 6 carries a loop of sewing thread downwards through the work to be sewn, and the associated looping mechanism passes the loop around the bobbin. When the needle rises again the loop is pulled into the thickness of the work and also raises thebobbin thread into the thickness of the work, so that conventional lock stitching is effected. Each looping mechanism is continuously rotated about a vertical axis coincident with the axis of the associated bobbin. The means for causing rotation of the looping mechanisms is described below.

Although the actual constructional details of the bobbins and looping mechanisms are well known, their disposition in relation to the remainder of the machine is an important feature of the present invention. The axes of rotation of the looping mechanisms and their associated bobbins are indicated by the referencenumerals 8 and 9 (see FIGS. 3 to 6 inclusive). The axis 8 of one bobbin is disposed to the rear of the transverse vertical plane, indicated in FIGS. 3 and 5 by the reference numeral 10, containing the axes of the

needles

5 and 6, while the axis 9 of the other bobbin is disposed in front of the plane 10. When the

needles

5 and 6 are in the middle of their lateral swinging travel the needle 5 and the axis 8 are in a verticalplane normal to the plane 10, and the needle 6 and the axis 9 are in a parallel vertical plane also normal to the plane 10. When the needles descend in use they pass adjacent to the peripheries of the bobbins. In normal use the needles descend only when they are atthe ends of their lateral swinging travel, but as their swinging movement is in the plane 10 and is tangential to the bobbins there is no difficulty in causing the looping mechanisms to pick up the loops of sewing thread which have been carried downwards by the needles, irrespective of the extent to which the needles are swung laterally from their mean positions, it being understood that the maximum lateral travel of the needles is relatively small compared with the distance of each of the bobbin axes 8 and 9 from the plane 10 of the needles.

The looping mechanisms are rotated by

tubular shafts

11 and 12 which are co-axial with the looping mechanisms and extend downwards from the looping mechanisms. The shaft 11 carries a toothed wheel 13 near its lower end, and the shaft 12 carries a similar toothed wheel 14 near its lower end. The lower ends of the

shafts

11 and 12 are mounted in bearings in the lower limbs of L-shaped

brackets

15 and 16 respectively. An internally toothed timing belt 17 extends around the

wheels

13 and 14 and also extends around a similar wheel 18 fixed on a vertically extending driving shaft 19.

The bobbin mountings, looping mechanisms, and associated parts including the L-shaped

brackets

15 and 16, are on an open-work frame 20 which extends generally horizontally beneath the bed 7 of the machine. Towards the rear of the frame 20, behind the axis 8 of the rear looping mechanism, are two trunnions 21 having a common horizontal, transverse axis. The trunnions 21 enter complementary bearings in an adjacent part 22 of the-bed 7 of the machine and enable the entire bobbin assembly to be swung between the position of use, described above and illustrated in the Figures, and a position in which the bobbins are readily accessible beneath the bed 7 of the machine. Thus when the bobbin thread is exhausted the empty bobbins can be removed and can be replaced by full bobbins. A particular advantage of this arrangement is that this removal and replacement can be effected without disturbing the work being sewn.

In order to avoid the need for disconnecting the drive to the looping mechanisms when the frame 20 is swung downwards from its position of use, the driving shaft 19 projects downwards from a gear box 23 disposed to the right of the frame 20 and having an input shaft 24 coaxial with the trunnions 21. Bevel gears in the gear box 23 transmit rotation from the input shaft 24 to the driving shaft 19. The gear box 23 carries a forwardly directed arm 25 through which extend locating pins 26 fixed to the frame 20, and an adjusting screw 27. When the frame 20 swings about the axis of the trunnions 21 the gear box 23 swings with it about the axis of the input shaft 24, which is in fact the same axis. Thus when the frame 20 has been swung down to enable newly charged bobbins to be inserted and has been replaced again in its position of use, the timing of the looping mechanisms is unaffected and remains as it was before.

The input shaft 24 for the gear box 23 replaces the shaft for driving the looping mechanism normally provided in a conventional sewing machine. The input shaft 24 is itself driven in a conventional manner, by way of a toothed wheel 28 keyed to the shaft 24 and a timing belt 29 which extends through the pillar 2 and engages another toothed wheel 30 on the main driving shaft 31 of the sewing machine which extends transversely of the machine, in a horizontal direction, inside the arm 3 of the machine as shown in FIG. 1. Alternatively the drive may comprise a gear train in place of the timing belt and

toothed wheels

28 and 30.

The swinging frame supporting the looping mechanisms is held in its position of use by a spring-loaded plunger 32 at the front of the bed 7 of the machine and adapted to be released by an operator in front of the machine pulling a knob 33 on the plunger towards himself. The plunger 32 snaps back into position when the frame 20 is swung back to its positions of use. Accurately positioned stops 34 are provided to ensure that the frame returns exactly to its position of use.

The needle carrier 4 may be replaced by similar needle carriers adapted to support needles spaced apart by different distances. The machine may be adapted to use needles at any spacing between half an inch and one inch. In each instance the position of the left hand needle, 5, remains fixed while the position of the right hand needle, 6, varies. The bobbin and looping mechanism associated with the right hand needle 6 must be adjusted to conform with the spacing of the needles. To this end the bobbin mounting 35 together with its associated parts is adjustable relatively to the frame. The mounting 35 is formed with slots 36 through which securing screws 37 extend, and carries the L-shaped bracket 16 and the shaft 12 with its toothed wheel 14.

Adjustment of the position of the mounting 35 alters the position of the toothed wheel 14 so that additional adjustment is necessary to avoid the timing belt 17 becoming too tight or too slack. This additional adjustment is effected by bodily movement of the gear box 23 with its input shaft 24. Bushes 38 on the input shaft 24 are freed, the gear box is moved by rotation of the adjusting screw 27 so as to bring the toothed wheel 18 on the gear box driving shaft 19 to the desired position, and the bushes 38 are secured again in place.

The bobbins may be similar to those described in US. Pat. No. 3,601,073 assigned to the same assignee as the present application and there may be mechanism similar to that described in that patent and adapted to produce a signal or bring the machine to a halt when the bobbin thread is almost exhausted from either of the bobbins. Such mechanism is described below with reference to FIG. 13.

The machine 1 is driven in the following manner. The machine is mounted on a stand 30 on which an electric motor 40 is also mounted. The axis of the driving spindle of the motor 40 extends transversely of the machine and carries a pulley engaging a belt 41 which also passes round a larger pulley 42 on a principal shaft 42, parallel with the driving spindle and disposed a little to the rear of the machine l. The principal shaft 43 also carries a toothed wheel 44 which engages a timing belt 45 passing around a similar toothed wheel 46 on the right hand end of the main driving shaft 31 of the machine, immediately to the right of the upper part of the pillar 2 of the machine.

From the toothed wheel 44 the principal shaft 43 extends to the left, behind the machine ll, through a gear box 47 and then to an eccentric device 48 where it terminates. The eccentric device 48 is coupled to a link 49 pivoted to one arm of a rocker pivoted on a feed roller shaft 51 in front of the device 48 but still behind the machine 1. An upwardly extending arm 52 on the rocker 50 carries a spring-loaded pawl 53 which cooperates with the uppermost part of a ratchet wheel 54 on the feed roller shaft 31. The arrangement is such that on each rotation of the principal shaft 43 the eccentric device 48 causes the rocker to oscillate to and fro so that the ratchet wheel 54 and the feed roller shaft 51 rotate through a small angle.

The feed roller shaft 5E extends to the left through a device 55 of known type preventing reverse rotation and through spaced parallel bearings 56. Between these bearings 56 the shaft 51 carries an upper feed roller 57. A lower feed roller 58 is disposed below the upper feed roller 57 and is mounted on a lay shaft 59 located by hearings in bearing blocks 60 which are urged upwards by compression springs 61 beneath the blocks. Cooperating gears l62 and 163 on the feed roller shaft 51 and the lay shaft 59 respectively to one side of the

rollers

57 and 58, cause the feed rollers to rotate in unison in opposite rotational directions. When the sewing machine assembly is in use the work passes from the sewing station, that is the place where the stitches are formed, to the

feed rollers

57 and 58 and is frictionally engaged by the rollers which pull the tape towards the rear of the machine between the formation of each of the two stitches formed simultaneously by the two

needles

5 and 6. The

feed rollers

57 and 58 may be ribbed to ensure that the tape does not slip, and the upper roller 57 may be circumferentially grooved as illustrated to allow the eyes sewn onto the tape to pass between the rollers without being damaged.

A rod 62 carrying eccentrics at its ends is mounted to the rear of the upper feed roller 57 and can be manually rotated by means of a handle 63 to cause the lower feed roller 58 to be pressed downwards, against the action of the compression springs 61, whereby the feed rollers are spaced apart sufficiently to enable the tape to be removed and replaced by new tape as desired. To this end the eccentrics on the rod 62 bear on vertical rods 64 which in turn bear on the end of pivoted arms 65, the central parts of those arms pressing down the bearing blocks 60.

That part of the assembly thus far described enables two parallel lines of uniform stitching to be formed in a length of tape. In the production of eye-tape, however, it is necessary periodically to stop the tape feed while the

needles

5 and 6 are caused to swing from side to side. For this reason mechanism is provided which enables the

feed rollers

57 and 58 to stop their intermittent rotation during a predetermined number of revolutions of the principal shaft 43. This mechanism comprises means for lifting the spring-loaded pawl 53 from the ratchet wheel 54. The pawl 53 is pivoted at 66 to the rocker 50 and has an extension 67 beyond and behind its pivot point which can be engaged by an appropriately shaped finger 68 (see FIG. 1) which presses the extension 67 downwards and prevents the pawl 53 touching the ratchet wheel 54. The finger 68 is disposed at the left-hand end of a horizontal, transverse arm 69 pivoted at its right-hand end to a fixed bracket 70, the pivot axis extending horizontally in a front-toback direction. A second arm 71, fixed to the arm 69 extends from the pivot upwards and to the right. Its

right-hand end co-operates with a cam 72 with a suitably shaped edge and mounted on a horizontal cam shaft 73 which extends rearwards through the gear box 47 mentioned above and through which the principal shaft 43 also extends, though at right angles to the cam shaft. The arm 69 is urged upwards by a helical tension spring 74.

The cam shaft 73 is intermittently rotated through 180 and the mechanism for causing this rotation is to the rear of the gear box 47. The cam shaft 73 extends through a tubular shaft 75 in the gear box, the tubular shaft carrying a worm wheel 76 which is driven by a worm 77 on the principal shaft 43. Thus the tubular shaft 75 rotates continuously when the machine is in operation. At its rear end, just to the rear of the gear box 47, the tubular shaft 75 has keyed to it a driving chain-wheel 78 which drives a roller chain 79. The chain 79 also passes around a series of freely rotatable chain-wheels 80 at the rear of the assembly, as shown in FIG. 11. When the pattern of eyes on the eye-tape is to be changed the chain 79 is replaced by another chain, and as the various chains may be of different lengths the chain-wheels 80 are mounted so that their positions can be adjusted to accommodate the different lengths. Whatever arrangement is adopted, however, the chain is always constrained to extend around at least 180 of the driving chain-wheel 78.

Mounted on the chain 79 at predetermined intervals are rearwardly projecting driving members 81 (see FIG. 1) which are conveniently shaped like a pair of adjacent chain rollers interconnected by links. As any of the driving members 81 passes round the driving chainwheel 78 it enters a peripheral groove in a drive cam 82 keyed to the cam shaft 73 immediately behind the driving chain-wheel 78, the cam shaft projecting to the rear of the tubular shaft 75. The drive cam 82 has two such grooves at 180 intervals around its circumference and the arrangement is such that each driving member 81 on the chain-wheel 78 rotates the drive cam 82 and cam shaft 75 through exactly 180. Each groove is asymmetrical, having a gradually inclined portion along which a driving member 81 can pass as it enters the groove, without causing rotation of the drive cam 82, and a radially directed driving portion 83 which is engaged by a driving member. Mounted behind the drive cam 82, and fixed to it, is a notched disc 84 which is normally engaged by a spring-loaded pawl 85. When the pawl 85 enters a notch in the notched disc 84 it prevents rotation of the disc and of the cam shaft 73. The arrangement is such that as each driving member 81 on the chain approaches the drive cam 82 it raises the pawl 85 from a notch in the notched disc 84 and thus frees the drive cam, cam shafts and notched disc for rotation. Each driving member 81 is constrained by a suitably positioned chain-wheel 86 to leave the driving chain-wheel 78 in a direction generally radially outwards from the driving chain wheel so that at the end of each half revolution of the cam shaft 73 the driving member is removed radially from the groove in the drive cam which it had been occupying and allows the cam shaft to stop immediately. As the cam shaft 73 stops, the pawl 85 drops into the next notch in the notched wheel 84 under the influence of its springloading.

Rotation of the cam shaft 78 also controls the lateral swinging movement of the needle carrier 4. The cam shaft 73 projects frowards from the gear box 47 towards the pillar 2 of the sewing machine, and carries a chain-wheel 87 at its forward end. A chain 88 extends around the chain-wheel 87 and around a further chainwheel 89 of the same diameter at the rear end of a shaft 90 which extends forwards beneath the arm 3 of the sewing machine and carries an edge cam 91 at its forward end (see FIG. 12). The edge cam 91 is engaged by a cam follower 92 on an arm 93 which is pivoted at 94 to a bracket on the arm 3 of the machine and is coupled to a depending arm 94. A link 95 connects the lower end of the arm 94 to a rocker frame 96 pivoted at its upper end, 97, to the arm 3. A vertically reciprocating rod 98 is mounted on the frame 96 and the needle carrier 4 is secured to its lower end. The rod 98 is reciprocated in a conventional manner. Eacn time the cam shaft 73 rotates through 180 as described above the edge cam 91 also rotates through 180 and in doing so causes the

needles

5 and 6 to swing laterally, between stitches, in accordance with a predetermined pattern.

As can be seen in FIG. 1 a disc 99 is secured to the shaft 90 between the chain wheel 89 and the arm 3 of the machine. The disc 99 and its associated parts are shown in FIG. 13. The disc is formed with a peripheral notch which can be entered by a follower 100 mounted on one arm 101 of a two-armed lever pivoted at 102 to a plate 103 secured to the arm 3 of the machine (not shown in FIG. 13). The arm 101 is urged upwards by a helical tension spring 104. The other arm, 105, of the two-armed lever carries an adjustable stop 106 and an operating member 107 for a micro-switch 108 secured to the plate 103. A probe 109 depends from the end of the arm and extends through a fixed guide 110. The lower end of the probe 109 lies in the path of the tape issuing from the sewing station. Below the probe 109 in a plate 111 pivoted to the bed 7 of the machine about a horizontal transverse axis spaced to the rear of the probe. The plate 111 has a depending lever 112 which is linked by means not illustrated to fingers which can bear on the end plates of the bobbins. The mechanism resembles that which is the subject of the aformentioned U.S. Pat. No. 3,601,073. When the bobbins are charged with thread their end plates are held in place by the thread and prevent significant movement of the fingers and of the plate 111. Thus, each time the probe 109 is free to move downwards, the disc 99 being in the position illustrated, the probe is prevented by the tape from moving downwards so that the follower 100 does not enter the notch in the disc and the micro-switch 108 remains actuated. If, however, the bobbin-thread is exhausted or nearly exhausted the end plates of the bobbins are free to move. Then, when the disc 99 is in the position illustrated the spring 104 moves the arm 101 upwards, the follower 100 entering the notch as illustrated. The arm 105 tilts to release the operating member 107 from the micro-switch 108, and the opening of the switch causes the motor 40 to be switched off. The probe 109 pushes the tape downwards and tilts the plate 1 1 1 so that the lever causes the fingers to move.

The cam shaft 73 controls one further device, and this is a device for inserting metal eyes into folds in the eye-tape immediately before they are sewn in place. The device is driven by a face cam 113 on the cam shaft 73 between the edge cam 91 which controls the pawl 53 driving the ratchet wheel 54 on the feed roller shaft 51, and the chain-wheel 87. In order to appreciate the nature and operation of the eye-insertion device it is first necessary to understand the details of the tape and of the eyes and the means by which they are fed to the device.

The tape itself, that is the fabric part of the finished eye-tape, is of composite construction, being formed from bands of materials. Rolls of these bands are mounted in front of the machine in alignment with the sewing station and the feed rollers. The bands of materials are guided to the sewing station through appropriate fixed guides (not shown) and, in some cases, through folding devices (not shown) which fold the bands as they are drawn through fixed folding guides and then crease them as they pass between creasing rollers one of which is spring-loaded towards the other. To ensure the correct tensioning of the bands at all times the creasing rollers are driven in synchronism with the feed rollers. There will now be described with reference to FIGS. 14 and 15 a typical tape comprising four bands of materials, three of which are bands of the same textile material but of different widths, while the other band is a band of non-textile, fibrous stiffening material.

The width of the band 114 of stiffening material is substantially that of the finished tape and this band is not folded. The broadest band of textile material 115 is twice that width. The central part 116 thereof lies beneath the band 114 of stiffening material, and its marginal parts, one of which 117 is twice as broad as the other 118, are folded towards each other over the top fo the stiffening material, their edges just meeting. The band of textile material 119 which is of intermediate width overlies the meeting edges of the broadest band 115. The intermediate band 119 extends over much of the narrower part 118 of the broadest band 115, but does not extend to the edge of the assembled tape. The intermediate band 1 19 also extends over about half the width of the broader part 1 17 of the broadest band 115 and its marginal portion 120 is folded under so as to present a folded edge. As described in greater detail below, the attachment portions of one row of eyes are tucked beneath this folded edge of the band 119 of intermediate width, the operative portions of the eyes projecting from between the bands.

The narrowest band 121 of the three textile bands is folded so that one marginal part 122 thereof lies beneath the entire central part 123 thereof, while the other marginal part 124 extends partially beneath the other two parts 122 and 123. Thus one portion of the folded hand 121 has two thicknesses of material while the other portion has three thicknesses. The folded band 123 is a little less than one third of the width of the band 114 of stiffening material and overlies that part of the band 116 of intermediate width which is not folded, and also overlies the narrower part 118 of the broadest band 115. That edge of the narrowest band 121 where there are two thicknesses of material is aligned with the adjacent edge of the broadest band 115, while the attachment portions of a second row of eyes are tucked beneath that edge of the narrowest band where there are three thicknesses of material, the operative portions of the eyes projecting from beneath the narrowest band and lying on top of the intermediate band.

The

various bands

114, 115, 119 and 121 are sewn together at the sewing station by two parallel lines of

stitches

151 and 152. Between successive eyes the lines of stitches are closely adjacent to those edges of the narrowest and intermediate bands from which the operative portions of the eyes project, one line of stitches 151 interconnecting all the bands together and the 152er 126 interconnecting all but the narrowest band together. When the needles swing to one side, the stitches are displaced a short distance further away from said edges.

The eyes are all of the same construction and one eye 125 is illustrated in FIG. 16. Each eye comprises a length of wire bent approximately in the shape of the outline of a letter T, the upright and cross-bar of which are relatively thick. That part 126 of each eye corresponding to the upright of the letter T constitutes the operative portion of the eye, while that part 127 of each eye corresponding to the cross-bar of the letter T constitutes the attachment portion of the eye. The ends of the wire are spaced a short distance apart at the centre of the upper part of the cross-bar 127, that is opposite to the centre of the operative portion 126.

As can be seen in FIG. 15, where any eye is present the adjacent line of stitches approaches the operative portion thereof alongside the attachment portion 127 and closely adjacent to the edge of the

band

119 or 121 overlying the attachment portion of the eye. Several transverse stitches 128, for example five, are formed by appropriate swinging movement of the needle carrier 4 while the tape feed is halted. A few stitches 129, for example three in number, are sewn inside the attachment portion of the eye, the needle being displaced by the swinging needle carrier into a position in which it is further from the edge of the overlying band than it was previously, and the tape feed operating normally. Further transverse stitches 130 are then formed, like the first group of such stitches 128, and finally the machine produces a further line of stitches 131 closely adjacent to the edge of the overlying band, this continuing to the next eye.

Due to the fact that the chain 79 may be readily altered or replaced, the spacing between the eyes can readily be altered as desired. The eyes may be disposed at uniform intervals or at different intervals following a repeating pattern. For example, as illustrated in FIG. 15, the eyes may be disposed in pairs along the tape, the two eyes of each pair being close together, and each pair being separated from the next by a wider interval.

Turning now to the supply of the eyes and their insertion into the tape, the eyes are preformed and are placed at random in a pair of rotating hoppers 132 (see FIG. 2). Formations in the hoppers 132 lift eyes from the mass of eyes in the hopper and feed them onto a rails of T-shaped cross-section (not shown), the web of the rail projecting between the ends of the wires from which the eyes are formed. Each rail is insulated electrically from the body of the machine and an electric circuit is formed through the eyes on the rail and the machine body. Means is provided such that if there is a break in the supply of eyes the circuit is broken and the machine is brought to a halt. Other electrical safety devices may also be provided which bring the machine to a halt if the eyes become jammed.

The eyes travel downwards along the rails to devices for inserting them into the folded tape immediately adjacent to the sewing station. These devices are shown in FIG. 17. There is one device on each side of the sewing station. Each device comprises a shallow arcuate channel 133 the ends of which subtend an angle of between l80 and 270 at the centre. The channel lies on the bed 7 of the machine and one end thereof points to the back of the machine and is disposed immediately in front of the sewing station. Each channel contains an arcuate slider 34 which can move along the channel, and the edges of which run in grooves in the side walls of the channel. The rails are so disposed as to discharge eyes into the channels at the positions indicated by the reference numeral 135. One end of each slider 134 is movable between the position illustrated in which it is adjacent to the bottom of the associated rail, and a position at that end of the channel by the sewing station. The arrangement is such that each time each slider 134 is retracted beyond the end of the rail one eye drops into the associated channel, the slider then moving the eye to the sewing station before returning for the next eye. The two sliders 134 are caused to reciprocate by appropriate linkages mounted on the bed of the machine and terminating at a cam follower which engages the face-cam 113 mentioned above. Each slider 134 is coupled to an arm 136 pivoted at the centre 137 of the arc of the associated channel 133. Each arm 136 is coupled by a link 138 of adjustable length to one corner 139 of a triangular plate 140 pivoted to the bed 7 of the machine at 141. The two plates 140 are linked to oscillate in unison by a transverse link 141 the ends of which are pivoted to the plates 140 at 142. The right hand one of the two plates 140 is also pivoted to a link 143, the other end of which is pivoted at 144 (see FIG. 1) to a link 145 which is in turn pivoted to the stand 39 at 146. An intermediate part of link 145 is pivoted to one end of a link 147 which extends rearwards beneath the arm 3 of the machine to join a centrally pivoted link 148 at 149. The link 149 is pivoted to a bracket on the frame at 150. The other end of the link 149 carries the cam follower (not shown) which engages the face cam 113. The timing of the devices is such that in use the eyes are inserted between the bands of the tape just before the first transverse stitches 128 are formed to secure the eyes in place, the sliders 134 remaining to locate the eyes in position while these transverse stitches are formed. The sliders 134 are then retracted while the remainder of the stitches needed to secure those eyes are formed.

It will be appreciated that the end portions of the shallow channels 133 containing the sliders 134 lie in between the appropriate bands of the tape just ahead of the sewing station, and that their presence does not prevent the correct arrangement of the bands at the sewing station.

A machine similar to that described above may also be used for making hook-tape, that is tape similar to that described above but having hooks in place of the eyes. The only difference in the machines relates to the devices for feeding the hooks to the bands as they ap proach the sewing station. Whatever devices are used it is preferred to insert both hooks laterally of the bands so that the attachment portion of each hook passes beneath the edge of a band while the bill extends over that edge. A device for feeding hooks to the bands is the subject of US. Pat. Application No. 319,058 filed Dec. 27, I972 and assigned to the same assignee as the present application.

In a modification of the machine assembly (not illustrated) the chain 79 carrying the driving members 81 is arranged to carry one or more pairs of such members so spaced that on each movement of the cam shaft 73 the shaft rotates twice through without a pause, that is it rotates through 360 uninterruptedly. The cams are then replaced by new cams so shaped as to carry out in a whole evolution what was previously effected in half a revolution.

It is to be understood that much of the mechanism described above, in particular the tape feed device, swing needle control, tape folding device, eye feed device, and timing arrangements may also be used in a machine assembly adapted to sew a single line of eyes or books or other fastening means onto a tape.

1 claim:

1. A lock-stitch sewing machine assembly of the kind including feed means for feeding work through a sewing station, a reciprocable needle carrier adapted to carry first and second needles disposed side by side in a plane transverse to the directions of work feed, means for reciprocating the' needle carrier so that the needles move lengthwise in that plane, first and second bobbin mountings and first and second drive means for looping mechanisms, associated respectively with the first and second needles, and defining first and second bobbin axes, the assembly being characterized in that the bobbin axes are at least substantially parallel with the needles, the first bobbin axis being substantially directly to the rear of the first needle and the second bobbin axis being substantially directly in front of the second needle, as considered in the direction of work feed through the sewing station, a common support for said bobbin mountings and looping mechanisms, and means for moving said common support downwardly away from the work station and the needle carrier to enable empty bobbins to be replaced by full ones.

2. A lock-stitch sewing machine assembly according to claim 1 in which one of the bobbin mountings with its associated looping mechanisms and the associated drive means is mounted on the common support for lateral adjustment in a direction parallel to the plane of the needles, to allow for variations in needle spacing.

to claim 1 in which said common support comprises a' frame mounted for downward swinging movement about a transverse axis to the rear of the sewing station.

5. A lock-stitch sewing machine assembly according to claim 1 in which the first and second drive means for the looping mechanisms are moveable with the bobbin mountings and in which a driving train from a fixed motor to said drive means remains engaged on movement of the bobbin mountings with their associated looping mechanisms, so that the timing of the looping mechanisms remains unaffected by downward movement and return of the common support.

6. A lock-stitch seweing machine assembly according to claim 5 in which the driving train includes a gear box with an input shaft coupled to the motor and an output shaft coupled to the drive means, the gear box rotating about the axis of the input shaft when the bobbin mountings are moved.

7. A lock-stitch sewing machine assembly according to claim 1 in which the feed means comprises a pair of to claim 8 in which the interrupting means is also synchronised with the operating of means causing the lateral movement of the needle carrier whereby in use transverse stitches are formed in the work.

10. A lock-stitch sewing machine assembly according to claim 8 in which the interrupting means is also synchronised with means for introducing fastening elemerits into the path of the work through the sewing station, whereby in use the fastening elements are sewn to the work with the aid of said transverse stitches.

Claims

1. A lock-stitch sewing machine assembly of the kind including feed means for feeding work through a sewing station, a reciprocable needle carrier adapted to carry first and second needles disposed side by side in a plane transverse to the directions of work feed, means for reciprocating the needle carrier so that the needles move lengthwise in that plane, first and second bobbin mountings and first and second drive means for looping mechanisms, associated respectively with the first and second needles, and defining first and second bobbin axes, the assembly being characterized in that the bobbin axes are at least substantially parallel with the needles, the first bobbin axis being substantially directly to the rear of the first needle and the second bobbin axis being substantially directly in front of the second needle, as considered in the direction of work feed through the sewing station, a common support for said bobbin mountings and looping mechanisms, and means for moving said common support downwardly away from the work station and the needle carrier to enable empty bobbins to be replaced by full ones.

3. A lock-stitch sewing machine assembly according to claim 2 in which the needle carrier is movable laterally, in the plane of the needles, tangentially with respect to the bobbin mountings.

4. A lock-stitch sewing machine assembly according to claim 1 in which said common support comprises a frame mounted for downward swinging movement about a transverse axis to the rear of the sewing station.

7. A lock-stitch sewing machine assembly according to claim 1 in which the feed means comprises a pair of intermittently rotatable rollers to the rear of the sewing station, operative to pull the work rearwards between the rollers.

8. A lock-stitch sewing machine assembly according to claim 7 in which there is interrupting means operative to interrupt the intermittent drive to the rollers to allow two or more stitches to be formed without movement of the work, the interrupting means being controlled by adjustable timing means driven in synchronism with the rollers.

9. A lock-stitch sewing machine assembly according to claim 8 in which the interrupting means is also synchronised with the operating of means causing the lateral movement of the needle carrier whereby in use transverse stitches are formed in the work.

10. A lock-stitch sewing machine assembly according to claim 8 in which the interrupting means is also synchronised with means for introducing fastening elements into the path of the work through the sewing station, whereby in use tHe fastening elements are sewn to the work with the aid of said transverse stitches.