DE2541378A1 - DEVICE FOR STOPPING A SEWING MACHINE - Google Patents

Description

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HÖGER - LEGAL RIGHTS - GRIESSBACH - HAECKER

PATENT LAWYERS IN STUTTGART

A 41 276 m

m - 163

September 10, 1975

Union Special Corporation 4OO North Franklin Street Chicago, 111. 60610 / USA

Device for stopping a sewing machine

The invention relates to a device for stopping a sewing machine, in which on a coupling with a main shaft connected to a drive wheel, a stop element is provided and pivot arms for actuating the clutch or are provided for the main shaft sustained engagement in the stop element.

It is known to provide stop devices on sewing machines, in which the main shaft of the machine of a first Drive wheel is released, after which the machine during a

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continues to idle for a short period of time until it stops abruptly will. However, the known devices of this type normally only allow a half Rotation of the main shaft after disengaging the clutch before the machine is stopped. As a result, the rotational speed has increased of the main shaft at the point in time when it is abruptly stopped is practically not substantially reduced.

It is the object of the invention to provide a stop device for sewing machines to propose in which the main shaft after disengaging its clutch longer than half a turn in Can continue idling before it suddenly stops.

This problem is solved by a camshaft rotating at a lower speed than the main shaft non-rotatably arranged cam with two steps of different depths as well as by an engaging on the cam, connected to the pivot arms associated with the coupling or the stop element and pivoting the latter together Cam lever, whereby when the cam lever engages in the first stage initially only the clutch by means of the one The swivel arm is disengaged, while when the lever engages in the second stage, the other swivel arm also passes through Engagement in the stop element stops the main shaft.

According to the invention, two separate cam elements are also provided, which can be adjusted relative to one another and the stop device are assigned in such a way that the main shaft is still idling between one and one and a half revolutions

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can continue running before it is stopped abruptly. The idle time the main shaft is adjustable due to this construction, so that it is possible to tolerate manufacturing tolerances and to compensate accordingly when assembling each individual machine.

The by the greater idle time of the inventive The greater reduction in the speed of the main shaft caused by the stop device leads to the following advantages:

1. Less wear and tear on the machine parts associated with the stopping device.

2. Lower noise development at the time of stopping.

3. Smaller overstroke of the sewing machine.

4. Preventing the machine from going through a double cycle.

The stop device according to the invention is particularly suitable for group stitch machines or cyclic machines, as described, for example, in US patents 2,511,367, 2 609 773, 3 509 Ö38 are described. In addition to button sewing machines this group of machines also includes stapling machines such as those described in US Pat. No. 3,749,041 are.

The following description of preferred embodiments of the invention is used in conjunction with the accompanying drawings

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further explanation. Show it:

1 shows a side view of a sewing machine with a stop device according to the invention;

FIG. 2 is a horizontal partial sectional view of the sewing machine from FIG. 1;

Fig. 3 is a partial sectional side view of the machine of Figs.

4 shows an enlarged, exploded illustration of the stop device;

5 shows an enlarged front view of a cam of the stop device and FIG

Fig. 6 is a sectional view taken along line 6-6 in Fig. 5. '

The sewing machine 9 shown in the drawing comprises a vertical stand 10 with a base 11 and a Substructure 12. A workpiece carrier arm stands horizontally from the base 11 13, which is provided in the usual way with a gripper and thread cutter (not shown). Above of the arm 13 extends from the upper end of the stand 10, an overhanging arm 14, which at its free The end is provided with a sewing head 15. The sewing head 15 includes a vertically reciprocating needle bar 16 on which one Sewing needle is attached.

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In the base 11, a main shaft 18 is rotatably mounted drives the needle, the hook, etc. via conventional gear means in order to carry out the desired stitch formation processes, for example attaching a button to a workpiece. Since these agents do not form part of the invention, they are not further described here.

The main shaft 18 carries an eccentric 19, which with each revolution the main shaft pivots a member 20 back and forth over a certain arc. During the stitch formation cycle of the sewing machine the link is pivoted back and forth while idling and has no function. After finishing a However, stitch formation cycle is the lower end of a connecting rod 21 to the left in the position shown in FIG displaced so that a shoulder 22 of the rod 21 comes into the path of a laterally protruding part 23 of the link 20. At this point in time, the pivoting of the link 20 by the eccentric 19 causes the connecting rod 21 to move downwards.

The upper end of the linkage 21 is articulated to one arm of a lever 25, v / which the ventilation of a button clip is used and is pivotably mounted on a bolt 26 in the arm 14. The forward arm 27 of the lever 25

one
downwardly extending rod 28, the lower end of which extends laterally and carries a roller 29. The roller engages the underside of a hook-shaped rod 30 which is connected to the mechanism 31 of the button clip. This mechanism can be designed, for example, as it is described in the US patents mentioned at the beginning. He

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is held pivotably on the machine frame by a rod 32. The mechanism 31 is normally during one Sewing cycle biased downward by a spring 33. When the rod 28 is raised upwards and in turn the rod 30 leads upwards, the mechanism 31 pivots about the rod 32 and thereby removes a button holding the button Part of arm 13.

During a sewing cycle, the lower end of the linkage 21 is normally restrained in a position to the right of FIG the position shown in Fig. 1, so that the shoulder 22 of the linkage outside of the path of the laterally directed Part 23 of the link 20 is located. However, when the machine is stopped, those parts take those shown in FIG position shown. After starting the machine, the lower end of the linkage 21 (in Fig. 1) is moved to the right. This is done in that an operator actuates a pedal or a toggle lever, which turns one in a counterclockwise direction ensuing pivoting of an oscillating shaft 34 to which an arm 35 is attached. The lower end of the arm 35 is articulated to a rod 36, the other end of which is articulated to the lower end of the rod 21. Shortly before Termination of a certain number of stitches and the automatic When the sewing machine is stopped, the oscillating shaft 34 (in FIG. 1) is pivoted clockwise, so that the linkage 21 returns to the position shown in Fig. 1 and the shoulder 22 in the path of the laterally directed part on link 20 brings. Accordingly, the next revolution of the main shaft 18 of the eccentric .19 when pivoting the link 20 cause the part 23 to engage the shoulder 22 of the rod 21 and press it down. this

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leads, as mentioned above, to a counterclockwise pivoting of the lever 25, whereby in turn the roller 29 arranged on the rod 28 engages the rod 30 and this raises together with the mechanism 31 of the button clamp. to at this point the machine is automatically stopped.

As can best be seen from FIGS. 2 and 3, on one side of the machine there is a swivel arm which actuates a ram 37 is provided, which is fastened in a rotationally fixed manner on the oscillating shaft 34. The pivot arm 37 carries a rod 38, at the end of which a the stopper serving plunger 39 is attached. A plurality of resilient washers 40 (Belleville washers) mounted on the Rod 38 are arranged, give the plunger 39 a bias (in Fig. 3) to the left. The swivel arm 37 is also firmly connected to a further pivot arm 41, the free end of which is provided with a cam surface 41a (FIG. 2) is. This cam surface is used to actuate a conventional friction clutch, which the main shaft 18 with one of a drive source in rotation drive wheel 42 releasably connects. The clutch includes a clutch disc that is connected to a stop element in the form of a disk 43, which in turn is non-rotatably seated on the main shaft 18. The disc 43 is provided with a claw 44 as well as with a pawl 45 (Fig. 3), which when the machine is stopped with the Plunger 39 work together. The plunger 39 is biased towards the disc 43 by a spring 46, one of which The end is connected to the pivot arm 37, which is used for stopping, and the other end of which is connected to the machine frame.

At the other end of the oscillating shaft 37 opposite the swivel arm 37, a cam lever 47 is arranged in a rotationally fixed manner,

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which carries a cam follower 48, which is best seen in FIGS. The cam follower 48 is arranged so that it engages the edges of two cam disks 49 and 50 which form a cam and which are on a camshaft 51 are attached. The disk 49 is held firmly on the hub 52 of a gear 53 by a snug fit. The disk 50 fits loosely over the hub 52 and is in turn provided with a hub 54. The cam disks 49, 50 are opened by screws 55 the camshaft 51 held, the screws 55 through threaded openings in the hub 54 as well as elongated Openings 56 in the hub 52 pass therethrough.

A hub 57, which is part of the cam plate 4 9, serves the maintenance of the correct distance between the disks 49 and 50. Between the disks 49 and 5o is an adjustable Shoe 58 is arranged, which is pivotably attached to the disk 50 at one end by means of a screw 59. An elongated, peripherally extending opening 49a in the cam disk 49 provides a free space and thus easy access to Screw 59. At its other end, the shoe 58 can be optionally fastened in one of two positions by means of a screw € 0. The screw 60 runs through one of two bores 61, 61a in the cam disk 50.

The cam disk 49 has two recesses 62 and 63 provided on its circumference, the recess 62 being made up of two stages 64, 65 and the recess 63 consists of two steps 66,67. As can be seen from FIGS. 4 and 5, the recesses 62 and 63 are identical to each other and mutually offset by 180 °. Levels 64 and 66 are slightly lower than levels 65 and 67.

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The cam disk 50 is provided with two identical, diametrically opposite recesses 68, 69, the Shape of the recesses 62, 63 is different. The recesses 68, 69 are generally aligned with the recesses 62 and 63 aligned when cams 49 and 50 are positioned on camshaft 51. The diameter of the Disks 49 and 50 are the same and are related to the position of the cam lever 47 in such a way that when the cam follower element rests 48 at the edges of the disks 49, 50, the oscillating shaft 34 is in such a position that the plunger 39 is kept out of contact with the stop serving disc 43.

When the shoe 58 assumes the position shown in FIGS. 3 and 5, it blocks or covers the recess 63 so that the machine runs through a full sewing cycle, e.g. executing 16 stitches before stopping. Through this a button with four holes can be sewn on. For example, if a button with two holes is to be sewn on, the shoe 58 is raised and held on the disk by means of the screw 60 extending through the bore 61a. If the Shoe 58 is in this position, the recess 62 is also open and the machine is stopped after every eight stitches.

When the sewing machine is in its starting or stop position, take the pivot arm 37 used for stopping and the cam disk 49, 50 the positions shown in FIGS. 1 and 3. The operator presses to initiate a sewing process a (not shown) pedal down, which by a

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Chain 70 is connected to a lever 70a. The lever 70a is in turn pivotable on a projection 71 of the substructure 12 stored on the sewing machine. The lever 70a pivots in Counterclockwise, with a pin 72 arranged on it on a downwardly extending arm 73 of the pivot arm 37 attacks and rotates it clockwise. As a result, the plunger 39 is disengaged from that which is used as a stop element Disk 43 brought. At the same time, the cam surface of the pivot arm 41 assigned to the coupling acts on the drive wheel 42 a, so that the clutch is engaged and the driven wheel 42 is connected to the main shaft 18, which in turn running around.

As can be seen from Fig. 1, the cam lever 47 is pivoted counterclockwise so that the cam follower 48 from the lower step 64 of the recess 62 of the disk 49 got out. The machine now begins the sewing cycle with the cam follower 48 resting on the peripheral edges of the cam 49, 50 seated. The camshaft 51 is rotated clockwise by a gear provided in the base of the machine driven so that the cam disks 49, 50 each perform one revolution when the main shaft 18 sixteen revolutions power. The speed ratio of shafts 51 and 18 is therefore 1: 16. (The reduction gear between shafts 18 and 51 can be seen from Fig. 2.)

The machine driven by the wheel 42 now continues to run until the recess 62 of the cam disk 4 9 the cam follower 48 approaches. Now the cam follower 48 falls from the peripheral edge of the cam disks 49, 50 onto the Step 65 of the disk 49. The associated with this collapse,

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relatively small movement of the cam lever 47 pivots the oscillating shaft 34 clockwise. As can be seen from Fig. 3, the pivot arm 37 is pivoted a little in this clockwise direction, whereby the plunger 39 is closer to the disc 43 arrived. The swivel arm 41 is swiveled sufficiently far so that the drive wheel 42 disengages from the clutch and the main shaft 18 detaches. At this point in time, the sewing machine still has about 1 to 1-1 / 2 revolutions in the sewing cycle to execute. The sewing machine, which is now separated from the drive wheel 42, only runs in the Idle further. The position of the plunger 39 is still far enough away from the disc 43 at this point in time, so that the claw 44 and the pawl 45 can move past the plunger 39 in a clockwise direction.

As can be seen from FIG. 1, the further rotation of the cam disks 49 and 50 now causes the cam follower element 58, falling from level 65 to level 64 floor. Through this The pivot arm 37 and the ram 39 now also reach their end position in which the machine is stopped. At this point in time, the disk 43 still has to perform approximately half a revolution before the claw 44 and the pawl 45 cooperate with the ram for the purpose of stopping the machine. Continue at this point as above already mentioned, the mechanism 31 of the button clamp opposite the arm 13 is raised so that the operator can remove the sewn button and a new button for the next Can introduce sewing cycle.

The advantage of the invention lies not only in the increased idle time of the machine at the end of the sewing cycle, but also

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in that this idle time can be adjusted. This is done by adjusting the disk 50 relative to the disk The disc 50 is provided with a curved circumferential slot 80 (FIGS. 4 and 5). Through this slot 80 runs a Screw 81 through which, after passing through a spacing ring 82, is screwed into a threaded hole 83 in the disk 49 is. The screw 81 serves to clamp the washer 50 in the adjusted position on the washer 49. the Screws 55 also serve to clamp the washers 49 and 50 together, in addition to securing them Washers on camshaft 51.

About the position of the cam disks 49, 50 relative to the camshaft 51, only need the screws55 to be solved. The screw 81 remains in the tightened state in order to maintain the relative position between the cam disks 49 and 50 to prevent change. To adjust the relative position between the cam disks 49 and 50, the screw 81 must be loosened together with the screws 55. By adjusting the cam 50 with respect to of the disk 49, the distance D (FIG. 5) is optionally increased or decreased.

In Fig. 5, the cam 50 takes its one, counterclockwise calculated end position. The distance D is minimal. In most practical cases, the cam disc will 50 is set approximately in the middle of the adjustment range. In the further description of the mutual adjustment of the Cam disks 49 and 50, it is assumed that the disk 50 is in its central position.

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By turning the cam disk 50 clockwise, the distance D is increased, while by turning the Disk 50 in the opposite direction the distance D is reduced. An enlargement of the route D leads to the cam follower 48 is more likely to drop to level 6 5, thereby reducing the idle time of the machine at the end of the sewing cycle is enlarged. This in turn causes the sewing machine speed at the time of stopping is less than when the cam disks were adjusted above. When the cam disk 50 is rotated relative to the disk 49 in the opposite direction, the idling time of the machine becomes shortened and the revolving speed of the machine increased at the time of its stop. With the one shown Embodiment can reduce the idle time of the machine on At the end of the sewing cycle can be adjusted by one to one and a half revolutions. When rotating the cam disk 50 is also the shoe 58 rotates with it. If the shoe 58 is to be adjusted, the elongated hole 59a provides access to the screw 59, and although in every position of the disk 50 relative to the disk 49. If the shoe 58 is to be replaced, the cam no discs 49 and 50 are removed from the camshaft 51.

It follows from the foregoing that by adjusting the relative positions of the cam disks 49 and 50, the idle time the sewing machine can be easily adjusted to avoid tolerance differences, how they can occur in the manufacture of the individual parts and in the assembly of the machine to compensate. If, for example, one machine has been assembled, it results in higher frictional forces than another Machine occur, this machine will be on a shorter one

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Idle time set as a lower friction machine. Furthermore, when replacing worn machine parts, the idle time can again be adjusted accordingly will.

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Claims (1)

Λ 41 276 m Patent claims: Device for stopping a sewing machine, in which on one connected to a drive wheel via a coupling Main shaft a stop element is provided and swivel arms for actuating the clutch or for the Main shaft sustained engagement in the stop element are provided, characterized by an on one with lower speed than the main shaft (18) rotating camshaft (51) with non-rotatably arranged cam (49) two steps (65,64) of different depths as well as by one on the cam (49) engaging with that of the coupling or the stop element (43) associated pivot arms (41,37) connected and the latter jointly pivot Cam lever (47), when the cam lever engages in the first stage (6 5) initially only the clutch is disengaged by means of the one pivot arm (41), while when the lever (47) engages in the second stage (64) additionally the other swivel arm (37) by engaging in the stop element (43) the main shaft (18) persists. 2. Device according to claim 1, characterized in that the effective length of the first stage (65) is adjustable _f to change the interval between disengaging the clutch and stopping the main shaft (18). 3. Device according to claim 1 or 2, characterized in that the cam consists of two cam disks (49, 50), and the one cam (50) has a step (68) with a control edge extending between the ends - 16 - 609816/0678 Λ 41 276 m September 10, 1975 - 16 - the first stage (65) provided on the cam disk (49) is arranged. 4. Apparatus according to claim 1, 2 or 3, characterized by means (81) for mutual attachment of the Cam disks (49, 50) in selectable angular positions and by means (55) for the common fastening of the Cam disks (49, 50) in a selectable angular position on the camshaft (51). 5. Device according to one of claims 1 to 4, characterized in that the cam disks (49, 50) are concentric have overlapping hubs (52,54). 6. Apparatus according to claim 5, characterized in that at least one screwed into the outer hub (54) Screw (55) through an opening (56) in the inner hub (52) and the fastening of the with the The outer hub connected to the cam disk (50) on the camshaft (51). 7. Device according to one of the preceding claims, characterized in that the cam disks (49, 50) several groups of stages (65, 64) and blocking means (58), by means of which at least one group of this stage can be made ineffective. 8. The device according to claim 7, characterized in that the blocking means as one between the cam disks (49, 50) arranged shoe (58) is formed. - 17 - 609816/0678 A 41 276 m m - 163 September 10th, 1975 -17- 9. Apparatus according to claim 8, characterized in that C50)
that the shoe / is pivotably mounted at one end and optionally attachable in different positions at its other end. 10. Device according to one of the preceding claims, characterized in that the on the camshaft (51) arranged cam consists only of the cam disk (49) and this disk preferably a blocking means (58) is assigned to ineffective one or more groups of the stages (65,64). 11. Device according to one of the preceding claims, characterized in that the main shaft (18) and the The camshaft (51) run parallel to each other and the swivel tub (37, 41) and the cam lever (47) are connected to one another Rocking shaft (34) are attached, which runs parallel to the main shaft (18) and the camshaft (51). 609816/0678 Blank page