US3361094A - Automatic device applied to a sewing machine for feeding the fabric - Google Patents

Description

Jan. 2,1968 L 90m 3,361,094

AUTOMATIC DEVICE-AP PLIED TO A SEWING MACHINE FOR FEEDING THE FABRIC Filed March 13, 1964 7 Sheets-Sheet 1 Jan. 2, 1968 L. BONO 3,361,094

AUTOMATIC DEVICE APPLIED TO A SEWING MACHINE FOR FEEDING THE FABRIC Filed March 15, 1964 7 Sheets-Sheet 2 Jan. 2, 1968 1.. BONO 3,361,094

AUTOMATIC DEVICE APPLIED To A SEWING MACHINE I FOR FEEDING THE FABRIC Filed March 13, 1964- '7 Sheets-Sheet 5 L. BONO 3,36 AUTOMATIC DEVICE APPLIED TO A SEWING MACHINE Jan. 2, 1968 FOR FEEDING THE FABRIC Filed March 15. 1964 '7 Sheets-Sheet 4 MSH Jan. 2, 1968 i BONO 3,361,094

AUTOMATIC DEVICE AI PLIED TO A SEWING MACHINE FOR FEEDING THE FABRIC Filed March 15, 1964 7 Sheets-Sheet 5 Jan. 2, 1968 L. BONO 3,361,094

AUTOMATIC DEVICE APPLIED TO A SEWING MACHINE FOR FEEDING THE FABRIC Filed March 15. 1964 7 Sheets-Sheet 6 FIG."

L. BONO 3,361,094 AUTOMATIC DEVICE APPLIED TO A SEWING MACHINE FOR FEEDING THE FABRIC Filed March 13. 1964 7 Sheets-Sheet 7 PRCT m WP m M W 1 V 4 1 1 m )L Av 4 w M 1. f 2 R m m r v m F v F 1 1 United States Patent Office 3,361,094 Patented Jan. 2, 1968 3,361,094 AUTOMATIC DEVICE APPLIED TO A SEWING MACHINE FOR FEEDING THE FABRIC Luigi B0110, Pavia, Italy, assignor to Necchi Societa per Azioni, Pavia, Italy Filed Mar. 13, 1964, Ser. No. 351,705 Claims priority, application Italy, Apr. 11, 1963,

23 Claims. (Cl. 112-2) The present invention refers to an automatic device applied to a sewing machine for feeding the fabric.

The present invention finds a large use when it is applied particularly to sewing machines for making buttonholes and for sewing on buttons and when the operator must execute, on a piece of fabric, a certain number of stitches at an adjustable mutual distance.

The main purpose of the present invention is therefore that of executing the positioning of a piece of fabric with respect to the needle of the sewing machine and, at the end of the first sewing cycle, of effecting the displacement of the fabric and its stopping in such a manner that the sewing machine may execute a new cycle of sewing on a further spot of the fabric at a predetermined distance from the former one and so on.

A further purpose of the present invention is that of effecting, after the completion of the sewing cycle, the automatic return of the operating members of the device to their respective starting positions of a new series of seams and in such conditions as to make the operation for replacing the work easier and speedier.

Another purpose of the present invention is that of providing an adjustment that is simple, sure and unlimited of the number of the sewing cycles and their reciprocal separation.

The device which forms the object of the present invention includes two carriages which are independent from each other. The first of them is connected to driving members, from which it receives the movement, and the second one follows the movements of the former when amidst the clamps assembled on the respective carriages there is stretched the piece of fabric on which the operator has to execute the series of sewings, whereas when the connection between the two carriages ends, which connection is effected by the piece of fabric, the second carriage is brought back to its starting position of the automatic cycle by means of a counterweight.

The reciprocal distances between the various seams is obtained at the end of every movement of the fabric, by a stem assembled on the first one of the above mentioned carriages engaging with extensions keyed on a rod at adjustable distances.

The device which forms the object of the present invention, since it is of an electromechanical nature, also comprises the electrical equipment which is typical of such devices, and which control and carry out, in the correct chronological order, the successive sewing operations and feeding operations of the fabric in order to accomplish in the most correct way the various stages composing the whole automatic cycle.

The following description is suitable for illustrating, in a more detailed manner, the purposes and the characteristics mentioned above and for giving evidence to new ones, and it refers to the application of the device to a sewing machine for sewing buttonholes.

The particular field of use of the device in question to which refer the drawings enclosed herewith has been chosen for the purpose of giving an example without intending by doing so, to reduce its field of use or to limit the importance of the invention.

FIGURE 1 represents a front view of the device;

FIGURE 2 represents a section according to line 11-11 of FIG. 1;

FIGURE 3 represents one of the two carriages of the device;

FIGURE 4 represents a detail of the carriage of FIG. 3;

FIGURE 5 represents a cutaway view of the counterweight;

FIGURES 6 and 7 represent two views of the second carriage of the device;

FIGURES 8 and 9 represent a detail of the carriage of the FIGS. 6 and 7 in two different movements;

FIGURE 10 represents a system of transmission by belts of the device of FIGS. 1 and 2;

FIGURE 11 represents a section of FIG. 10 according to line XL-XI;

FIGURE 12 represents a detail of the device of FIGS. 1 and 2;

FIGURE 13 represents in a schematic manner the mech anism for the emergency automatic stopping of the sewing machine; and

FIGURE 14 represents the functional diagram of the electric circuit of the device.

The device according to the invention includes a bed 1 on which is mounted a sewing machine 2 (FIGS. 1 and 2). The sewing machine is known and can be either a sewing machine for making buttonh-oles, a machine for sewing on buttons or any automatic sewing machine for making a cycle of seams.

The MAS electric motor for operating the sewing machine is connected to the main shaft 3 of the machine by means of a transmission belt 4 controlled by a belt-displacing lever 5; an electromagnet EMl can bring, by means of kinematic motion 6, said belt-displacing lever to a position corresponding to machine operation; a cam 7 in a known manner at the end of every cycle of sewing brings, by means of the finger 8, the belt-displacing lever 5 to a position in which the belt 4 is idle with respect to the main shaft 3 while a stopping element 9 operates in a known way for stopping said main shaft in an angular position corresponding to the stopping of the needle 10 of the machine upwards, outside the fabric, so as to allow displacements or the replacement of the fabric. The sewing machine 2 includes also a presser foot 11 which lowers in working position at the de-energisation of an electromagnet EMZ connected to said foot by means of a rod 12.

The fabric on which the sewing machine must execute a series of seams in cycles of stitches suitably distanced from one another is stretched between two clamps 13 and 14. At the end of every automatic cycle of sewing, the machine controls, as will be described in the following pages, the raising of the presser foot 11; the two clamps 13 and 14 must then cooperate one with the other for automatically displacing the fabric in the correct distance so that the various sewing cycles may take place at the desired mutual distance. After every positioning of the clamps 13 and 14, the sewing machine must start automatically a new sewing cycle in order that, after the series of the desired sewing cycles, the sewing machine must stop definitely and the clamps 13 and 14 must re turn automatically to their starting position and must be open in order to receive a new piece of fabric.

Since generally in the machines for making bottonholes or for sewing on four hole buttons during the execution of every cycle the presser foot 11 moves in a predetermined direction dragging with it the fabric, the two clamps 13 and 14 must obviously make said displacements possible. This is obtained in the device according to the invention by providing that the first one of said clamps, which will be called feeder 13, when reaching its successive positions may determine the distance between the various seams, and that the second clamp, which will be called tensor 14, besides cooperating with the former one for stretching the fabric, may follow the displacements of the fabric controlled by the presser foot 11.

The tensor 14 is in fact assembled on a carriage 15 which slides on a guide 16 provided on the bed It and is drawn towards a position corresponding to the end of the stroke against an adjustable stop 17, by a counterweight 18.

In FIGURE 2 the guide 16 is pivoted at the top of a rod 19 fixed on the bed 1 along which the counterweight 1S slides and against a stop 20 provided on the base of the sewing machine 2. The possibility that guide 16 may be turned with respect to the working position, although it is not indispensable to the functioning of the device, has been provided in order to facilitate the fastening operations of the fabric to the clamp 14, and it permits the bringing of the clamp itself to a position which is comfortable to the operator.

The clamp 14 which is illustrated in the FIGS. 3-4 comprises a jaw 21 directly fixed to the carriage 15 and a second jaw 22 assembled on a lever 23 which ts pivoted on the carriage 15 by means of the support 24 and the pin 25 and is pressed against the jaw 21 by means of a spring 26. A pin 27 driven with the lever 23 is engaged in the heliceidal groove 28 of a bushing 29 which is pivoted on the carriage 15 by means of a pin 3t) together with a lever 31, in order that by turning said lever from the position c towards the position d with spring 26 is stressed and the clamp is opened.

The counterweight 18 (FIGS. 2 and consists of a cylindrical block 32 which slides along the above mentioned rod 19 and is connected to the carriage 15 by means of a cable 33 engaged in the race of a small pulley 34 carried by said rod. At the end of its stroke the cylindrical block 32 penetrates into a bell 35 fixed in an adjustable manner to the lower end of the rod 19, and is braked by the gradually increasing resistance which a series of radial holes 36 provided along the bell oppose to the air flow which compresses into the bell itself. In fact, the holes 36 have diameters proportional to their distance from the bottom 37 of the bell 35.

Besides the radial holes 36, the bell 35 has the seat 38 of a micro-switch MSH which is opened by the cylindrical block 32 during its penetration stroke into the bell 35.

Said micro-switch, as will be described in the following pages, acts on the circuit of the remote control switch T1 which controls the starting of the sewing cycles.

The feeding clamp 13 is in its turn assembled on a carriage 39 which is slidable along two rods 40 and 41 of the bed 1 and comprises (FIGS. 6-9) a jaw 42 fixed directly to the carriage 39 and to a further jaw 43 which is assembled on a lever 44 freely pivoted on a pin 45 of the carriage itself. Lever 44 has a concave surface shaped according to two arcs of circle 46 and 47 suitably radiused with each other.

An operating lever 48, which can turn freely on a pin 49 which is in parallel with pin 45, has a hole 50 whose axis is perpendicular to the axis of said pin 49', within which are assembled one spring 51 and one small ball 52. When the operating lever 43 is in the position of FIG. 8, the small ball 52 presses against the arc of the circle 46 and opens the clamp 13; vice versa, when the operating lever 48 is in the position of the FIG. 9,

the small ball 52 presses against the arc of circle 47 and closes the clamp 13. On the carriage 39 which carries the feeding clamp 13 is articulated a connecting rod 53 (FIGS. 6, l0 and 11) placed between two transmission chains 54 and 55 to which the connecting rod is connected by means of the pin 56. The transmission chains 54 and 55 are stretched, in parallel with the rods 40 and 41, between the toothed wheels 57 and 59, and 58 and 60 respectively. The toothed wheels 59 and 69 are similar and are assembled in such a manner that they protrude on the facing ends of two coaxial small shafts 61 and 62 which are bushed on the supports 63, 64 assembled on the bed 1; the toothed wheels 57 and 58, which are similar, are assembled in such a manner that they protrude on the facing ends of two coaxial shafts 65 and 65.

Said coaxial shafts 65 and 66 are supported by the box 67 and receive the movement from a motor MD through an electromagnetic clutch and a reducer not shown in the figures and contained by said box.

When said electromagnetic clutch is energized, the two chains 54 and 55 move simultaneously in the direction of the arrow x and displace the carriage 39 along the rods 4% and 41 downwards. On the carriage 39 is fixed a striker 68 capable of limiting the possible oscillations of the connecting rod 53 as far as it is necessary in order that it may transform the movement of the chains in the direction of the arrow x in alternating movements, going and return towards the top of the carriage 39 along the rods 40 and 41 (FIG. 11).

In parallel with the rods 40 and 41 the bed 1 carries also a grooved rod 69, axially sprung (FIGS. 1 and 2). The springing of the rod 6-9 is made by a coaxial spring 70. Along said grooved rod are fixed, at an adjustable mutual distance, some small blocks 71a, 71b, 71c .711, each carrying an extension '72.

On the pin 73 of the carriage 39 is pivoted a small stem 74 (FIG. 6) whose race 75, adjacent to a surface 76, is directed towards the extensions 72 of the blocks 71 and is apt to engage said extensions owing to the effect of a spring 77.

The stem 74 consists of one of the two arms of an L shaped lever 78, and the spring 77 is anchored to a pin 79 of the carriage 39 and the pin 80 assembled on the other arm 81 of said lever.

As soon as the going movements of the carriage 39 downwards bring the stem 74 to receive in its own race 75 the extension 72 of one of the blocks 71, the grooved shaft 69 moves axially pressing the spring 70, and one of its fingers 82 presses on a microswitch MSE which controls the de-energization of said electromagnetic clutch contained by the box 67 and makes the carriage 39 idle. Immediately afterwards spring 70 pushes the rod 69 in the opposite direction in such a manner that its finger '82 presses another microswitch MSF controlling the functioning of the sewing machine. As we shall describe in the following pages, the functioning of the sewing machine starts when spring 70 has been released and when it has exactly positioned the carriage 39.

At the end of every automatic sewing cycle made by the sewing machine, an electromagnet A disengages the stem 74 from the extension 72 and energizes again said electromagnetic clutch in such a manner that the carriage 39 resumes its movement along the rods 40 and 41 (FIG. 12).

In the example of embodiment illustrated in the enclosed figures, said electromagnet A is assembled on the bed 1. Its movable core 83 ends into a rack 84- which is in connection with a toothed sector 85 fixed on an end of the grooved rod 69.

Besides the rack 84, the core 83 of the electromagnet A carries also a collar 86 placed in line with a microswitch MSB.

At the end of every automatic sewing cycle, the electro magnet A is energized for very short instants, in the manner which will be described hereunder, in order that while the electroswitch MSB controls the energization of the electromagnetic clutch the grooved rod 69 revolves around its own axis and disengages the extension of the stem 74, thus permitting, before returning to its original position, the translation of the carriage 39.

The alternate displacements of the carriage 39 and of the execution of the automatic sewing cycles by the sewing machine is repeated until a rod 87 carried by the carriage itself comes into contact with a cam 88 which is assembled in an adjustable axial position on a rod 89 in parallel with the aforementioned rods 40, 41, 69 (FIGS. 1 and 2).

The rod 87 is driven together with the already mentioned pin 49 of the carriage 39 and with a 'hand operating lever 90. To an arm 91 of said pin 49 is articulated a pull rod 92. A spring 93, which in FIG. 6 is anchored to said pull rod 92 and to the carriage 39, by means of the respective pins 94 and 95 makes the arm 91 adhere to a stop 96. The pull rod 92 carries a slot 97 in which is engaged the already mentioned pin 80 assembled on the arm 81 of the two-arm lever 78 which constitutes the stem 74. The slot 97 has sufiicient dimensions for permitting the stem to accomplish freely the necessary oscillations for engaging the extensions 72 of the small blocks 71. During these oscillations, a pin 98 of the stem 74 slides against a lever 99 due to the action of a spring 100 which is anchored to the same lever 99 and the above mentioned pin 79. when the rod 87 presses on the cam 88, or on operating the lever 90, the pull rod 92 rotates the two-arm lever 78 around the pin 73 in order that the pin 98, after having been sliding against the lever 99 engages itself in a catch 101 of said lever, thus excluding any possibility of contact between the stem 74 and the extension 72. The carriage 39 is then free to complete its stroke downward and to make the return stroke upward. At the end of the return stroke, a catch 102 carried by the bed 1 engages a pin 103 of the lever 99 and tensions the spring 100 and rotates said lever 99 around the pin 104 in order to move away its catch 101 from the pin 99 of the two-arm lever 78, so that at the beginning of the following downward stroke the carriage 39 stops as soon as the stem 74 engages the extension 72 of the block 71a.

When reaching the position of engagement of the stem 74 with the extension 72 of the block 71a, the carriage 3'9 presses on a microswitch MSG by means of the cam 105 as it will be described in the following pages, and prevents the machine from starting the execution of a new sewing cycle before a special hand control PM is operated.

The rod 87, besides permitting the speedy return of the carriage 39 to the starting position of engagement of the stem with the extension of the block 71a, controls also the opening of the clamp 13 to make the replacement of the fabric speedier. In fact, the operating lever 48 of said clamp carries a pin 106 (FIG. 9) which, when the clamp itself is closed, is in contact with the above mentioned rod 87.

When said rod revolves due to the contact with the cam 88 or the manual operation of its operating lever 90, it rotates also the operating lever 48 and opens the clamp 13.

At the opening of the clamp 13, the fabric, which connected said clamp with clamp 14, lets the latter return against the stop 17 due to the effect of the counterweight 18, so that both clamps are again in their starting position required for the execution of a new series of automatic sewing cycles.

On the sewing machine connected to the automatic device described above is provided the application of a mechanism for stopping the machine itself in case of emergency.

For this purpose an electromagnet I (FIG. 13) is energized either manually or by an automatic device which may be, for instance, that used for the automatic stopping of the machine when the upper thread snaps.

The electromagnet I is energized for a brief instant in 6 order that its movable core 107 which ends with an elliptic cam 108 may accomplish a travel downwards and a similar travel upwards, caused by the spring 109, at the deenergization of said electromagnet.

The two vertical travels in opposite directions are exploited in order to operate the mechanism for the emergency stop of the machine schematically illustrated in FIG. 13.

Said mechanism comprises a lever 110 pivoted on the vertical pin 111 within the bed of the sewing machine.

Said lever carries on one of its ends the pawl 112 which is placed in contact with the cam 108 and underneath it. The other end of said lever 110 is connected, by means of the pin 113, with the sliding rod 114 which is in its turn connected, by means of the pin 115, with the lever 116 oscillating around pin 117 which is carried by the bed of said machine.

The sliding rod 114 is kept in an intermediate position by two opposing springs 114 and 114" anchored with one of their ends to said rod and with the other end to the bed of the machine. Said lever 116 carries on its unpivoted end a rod 118 engaged within a shaped groove 119 provided on a lever 120 oscillating around a pin 121 carried by the bed of the machine. Said lever 120 presents, at one end, the steps 122, 123- and 124. Said steps are engaged by a tooth 125 rigidly connected to the above mentioned belt-displacing device 5.

Owing to the travel downwards of the movable core 107 of the electromagnet I, the spring 109 is compressed and the cam 108, with its surface 126, displaces the pawl 112 and, consequently, the lever 110 in the direction of the arrow y while the rod 118 kinematicall'y bound with said lever presses on the bent surface 127 of the shaped groove 119 forcing the lever 120 to oscillate in the direction of the arrow z against the action of the spring 128. The tooth 125, by means of the spring 129, falls, owing to the oscillation of said lever 120, from the step 122 to the step 123 and makes the beltdisplacing device 5 to accomplish a first movement producing, in a known manner, a reduction of the speed of the machine.

When the cam 108 is under the pawl 112 at the end of its travel downwards, the springs 114' and 114" bring the sliding rod 114 and the levers 110 and 120 back to their intermediate positions.

At the de-energization of the electromagnet I, the spring 1109 brings upwards the movable core 107 and the surface 126 of the earn 108 displaces the pawl 112 and the lever 110 in the opposite direction to that of the arrow y and the rod 118 makes the lever 120 accomplish a further oscillation in the direction of the arrow z, by pressing on the surface 127' of the groove 119.

The tooth 125 then falls, by means of the spring 129, from the step 123 to the step 124.

The belt-displacing device 5, which is rigidly connected to said tooth, makes a further movement and stops the machine.

The various stages of the working of the automatic device will now be described with reference to FIG. 14 which shows the functional schema of the electric circuit of said device.

A three-phase electric line feeds directly, when the general switch Ig is closed, the motor of the sewing machine MAS and the motor MD connected to the electromagnetic clutch represented with the letter C in the electric schema.

From two wires of the three-phase line, through a voltage stabilizer ST, is drawn the voltage for feeding a first length of circuit.

The same voltage, after having been rectified by the rectifier RDI, a second length of the circuit and feeds through the transformer TR and the rectifier RD2 a third length of the circuit.

At the closing of the general switch Ig and before starting the automatic cycle the two motors: MAS and MD work idly and the whole circuit is energized.

The only closed branch of the circuit is now that of the electromagnet EM2 which therefore turns out to be energized.

When the electromagnet EM2 is energized, the presser foot 11 (FIG. 2) is raised as it must be in order that the operator may place on the machine the piece of fabric on which the series of the sewing cycles are to be carried out. In order to start the automatic cycle we must press the start push-button PM. With this maneuver we close the branch of the circuit comprising the remote control switch T1 which energizes and operates at the same time its own contacts T11, T12, T13, T14, T15 and T16.

Thus T11 is closed to keep T 1 energized when the pressure of the operators finger on the push-button PM ceases.

T12 is closed in order to energize the electromagnet CA1 of the button-hole counting device which in normal working conditions does not work on the contact CA placed on the branch of the remote control switch T1.

The functions of the button-hole counting device will be specified more exhaustively in the following pages; for the time being it suffices to know that to every energization of this device there corresponds the release of one unit in a meter mechanism.

The electromagnet CA1 energizes every time that, owing to the energization of T1, contact T12 closes, that is at the beginning of every sewing cycle.

The energization of CA1 provokes, as already said, the release of a unit in a meter mechanism, according to a well known technique.

After a predetermined number of energizations, and only then, CA1 will go into action so as to commute its own contact CA.

Such devices are so well known in the technical field in general and in the automation field in particular, that there is no need here to speak about them more in detail.

The electromagnet CA1 has been surrounded by a rectangle so as to show that it influences its own contact CA in a particular manner; that is CA intervenes, in cooperation with other members (not shown), in order to effect the commutation of CA after a predetermined number of energizations undergone by it.

T13, inserted in the branch of the remote control switch T2 opens without altering, during the normal functioning of the automatic cycle, the electric state of said remote control switch T2.

T14 set in the branch of the electrom-agnet EM2 opens itself and de-energizes EM2. The presser foot 11 descends swiftly owing to the action of a spring which is not shown in the enclosed figures, as soon as EM2 is deenergized. T15, which is set in the branch of the relay R1 closes itself in order to discharge the condenser C1, as we shall explain more clearly in the following pages. T16 closes itself and energizes, with a certain dela the relay R4! which controls the closing of its own contact R41 set in the branch of the electromagnet EMl. EM]. energizes itself (FIG. 2) and operates the belt displacing device 5 through the rod 6. As a consequence of this operation the sewing machine starts functioning after the presser foot 11 has descended, since the energizations of the respective electrom-agnets EMi and EM2 have been delayed one from the other by means of the delay of RM.

The belt displacing device 5 in its movement for operating the sewing machine operates the two micro-switches F11 and F12, namely: F11, set in the branch of RSt, closes itself and energizes the delayed relay R5! which opens the contact R51 set in series with the remote control switch T1.

The remote control switch T1 tie-energizes operating its own contacts T11, T12 etc. in order to bring them back to the rest position shown in FIG. 14.

The contact T14 in the branch of EM2, owing to the delay of RSI, will be shut when F12, operated simultaneously with F11, will have already opened itself in order that the dc-energiz-ation of EM2 is maintained and the lowering of the presser foot 11 is ensured while the machine is sewing. T16, in the branch of R41, is now open and R42 is de-energized. To the de-energization of R4! there corresponds the re-opening of the contact R41 and EMl de-energizes itself. The machine continues functioning also after the de-energization of EMl because the system for the displacement of the belt 5 is held, mechanically and in a known manner, in the position where it had been brought owing to the energization of said electromagnet EM1 (FIG. 13) and remains there also after the deenergization of this electromagnet. At the closing of the micro-switch F11 the relay R5 is energized through the contact T23, which is always closed during the normal functioning of the machine according to the circuit: R6, T23, F11,

At the energization of R6, the contact R62 for the selfenergization of said relay R6 and the contact R61 set on the branch of the relay R1 close themselves in order to prepare the energization of this relay.

As shown in FIG. 13 the finger 8 ends with the lever and consequently said lever is driven, either by the action of cam 7, or by the action of the rod 118 actuated by the electromagnet I.

The action of the electromagnet EMI through the kinematic motion 6 (FIG. 2) has only the purpose of bringing tooth 125, which is connected with the beltdisplacing lever 5, to the step 122 (FIG. 13), to which position corresponds the condition of full speed of the machine.

Tooth 125, and consequently the belt-displacing lever, is then maintained in this position by means of spring 128; it will then be possible to bring again tooth 125 itself to the position corresponding to that of standing machine, either by the action of cam 7, at the end of the sewing cycle, or by the action of electromagnet I in case of emergency stopping.

A complete illustration of the working of earn 7 is contained in the US. patent application Ser. No. 247,639, now Patent No. 3,216,381.

At the end of the first sewing cycle, earn 7 intervenes in a known manner in order to shift the belt displacing device 5 and to stop the machine. Said system for displacing the belt 5, besides stopping the machine, operates the two micro-switches F11 and F12 opening again the first one and closing the second one; in other words, it arranges them in the respective position shown in the FIG. 14.

To the closing of F12 corresponds the energization of EM2 and the raising of the presser foot 11.

The energization of EM2 produces also (FIG. 2) the closing of M51 set in the branch of R1.

We have therefore the energization of R1 according to the following circuit: R1, C1, Pd, R61, MSI,

The energization of the relay R1 is rather short because the current in the branch of said relay passes only during the time when the condenser C1 is charged and the circuit is discontinued and R1 de-energizes itself when C1 is discharged (the condenser C1 is discharged at the closing of T15 when the remote control switch T1 is energized again).

To the energization of R1 corresponds the closing of the contact R11 and the energization of the electromagnet A in series with which R11 is placed.

The energization of A therefore is rather short because it is directly controlled by the short energization of the relay R1.

The displacement of the movable core of the electromagnet A at the energization of this magnet provokes in the manner which has already been described the release of the stem '74 of the expansion 72 of the collar 7112' in order that the carriage 39 may accomplish the first translation downwards as soon as the clutch C acts transmitting the movement to said carriage.

The clutch C starts its functioning simultaneously with the release of said stem from the extension 71a because said movable core of the electromagnet A in effecting with its movement said release presses also the micro switch MSB set on the branch of the clutch C, closing it for a short time.

During the short closing of MSB, the clutch C energizes itself through the circuit: C, MSB, MSE, At the closing of MSB, the relay R7 energizes itself and self-energizes respectively through the circuits:

R7, MSB, MSE,

R7, R71, MSE,

In this manner the clutch remains energized, despite the short duration of the closing of MSB, through the circuit: C, R71, MSE,

The relay R7, by energizing itself, opens its own contact R72 set in the branch of T1.

The belt displacing system 5 controlled by the cam 7 at the end of the sewing cycle operates, as already said, the micro-switch F11 set in the branch of the relay These operations have not an immediate eifect but serve only to prepare the energization of the remote control switch T1 for the automatic start of a new sewing cycle.

For the same purpose, when the carriage 39' starts the first movement of the fabric drags with itself the carriage 15 and the counterweight 18 which, when coming out from the bell 35, permits the micro switch MSH to close itself preparing the energization of T1. At the end of the first movement of the carriage, the stem engages the extension 72 of the collar 71b of the grooved rod 69 and presses said rod downwards in order that the finger 82 of said rod shuts for an instant the micro-switch MSF on the contact of the branch of the relay R2 and opens the micro-switch MSE set on the branch of R6. At the opening of MSE the circuit of the clutch opens so that the stem 74 of the carriage stops pushing the rod 69 which returns by means of the spring 7t? upwards displacing again MSF on the contact of R3 and closing MSE again.

The short opening of the micro-switch MSE in addition to the clutch C de-energizes also the relays R55, R? and R6 in order that the respective contacts R51 and R72 set on the circuit of T1 close themselves and R61 set on the circuit of R1 opens itself to be ready for operating again the energization of R1.

When the micro-switch MSF closes itself on the contact of the branch of the relay R2, energizes and selfenergizes said relay through the respective circuits:

+, R2, MSF, MSG,

+, R2, R21, F12,

at the energization of R2 the contact R22 closes.

In such a manner, when MSF returns to the contact of the branch of the relay R3, this relay energizes itself through the circuit:

+, R3, R22, MSF, MSG,

the energization of R3 provokes the closing of its own contact R31, the only one which is still open on the branch of T1.

The remote control switch T1 is thus energized again according to the circuit: T1, MSH, P31, Pa, R51, R72, Ca.

At the energization of T1 the above operations are repeated in order that the sewing cycles will follow the movements of the fabric from a sewing position to the following ones until the completion of all the sewing cycles.

After the last sewing cycle the carriage 3% in its displacement in the direction of the arrow x (FIG. 11) brings its rod 87 against the cam 88 carried by the rod 89. The stem 74 is hooked in such a position that it cannot interfere with the extensions 72 of the collars 71 in order that the clutch C, since it is no more energized by the micro-switch MSE, continues dragging the carriage 39 towards the starting position of the automatic cycle.

Before reaching the vicinity of the extension 72 of the collar 71a, the step 102 releases the stem 74 so that this can engage itself again with said extension 72 producing in the usual way the stopping of the clutch C.

At the same time, however, a cam carried by the carriage has produced the opening of the micro-switch MSG excluding every possibility of energization of the relay R3 controlling with its contact R31 the energization of T1 for the automatic starting of the machine. The rod 87 operates also the release of the fabric from the positioning carriage 39 in such a manner that the stretching carriage 15 due to the action of the counterweight 18 returns to its starting position and said counterweight entering the bell 35 opens the micro-switch MSH ensuring again the opening of the branch of the remote control switch T1.

When the operator has placed another piece of fabric on the machine in order to start a new automatic cycle, he must press the push-button PM again.

The automatic device which has been described above is provided with a mechanism to prevent the execution of a sewing cycle when the bobbin of the lower thread does not contain a sutlicient quantity of thread in order to end the cycle. Said mechanism consists of a counter of sewing cycles, which can be predisposed in such a man ner that after a certain number of these cycles, determined by way of experiment, there would intervene a means capable of operating the contact CA so as to open the branch of the remote control switch T1 in order that, failing the possibility of energizing this switch, the starting of a new sewing cycle would be precluded and shut wIth said contact CA a circuit comprising a warning light S1 and an acoustic signal apparatus S. After the replacement of the bobbin, the operator must set the counter to zero and displace contact A to the position of normal functioning on the branch of the remote control switch T. After these operations have been eifected, it will be possible to start a new sewing cycle manually by maneuvering the pushbutton PM. The machine can be stopped, in case of abnormal functioning, either manually by pressing the pushbutton PA or automatically by a device shutting the contact Tf. In any case the circuit of the relay R8 is shut either through PA or through Ty and said R3 is energized. The circuit of the relay R8 is constituted in such a manner that the energization of said relay would have a short duration. Said relay operates its own contacts R81 and R32; R82 closes itself and energizes the electromagnet I which stops the machine in a manner which has already been described (FIG. 13).

R81 closes itself and energizes the remote control switch T2 which operates its own contacts T21, T22 and T23.

T21 closes itself so as to self-energize T2 and main tain its energization when R81 opens itseif.

T22 opens itself so as to ensure the de-energization of the electromagnet EM2 and consequently to maintain the presser foot 11 lowered.

T23 opens itself in order to permit the de-energization of the relay R5t when the belt-displacing system 5 in stopping the machine opens the micro-switch F11 again and prevents said R5! from remaining energized through the branch of the relay R6.

To the energization of R5 corresponds the closing of the contact R51 on the branch of T1. This maneuver is indispensable because for operating the machine again we must energize T1 by pressing the pushbutton PM and self-energize it through the circuit: T1, T11, R51, R72,

CA, as it is the case at the beginning of the automatic cycle.

A provision has been made also for the non-automatic functioning of the device.

For this purpose it is sufficient to operate the switch pushbutton Pd.

With this operation we open the branch of the remote control switch T1 preventing this from energizing itself automatically for starting the sewing cycles following the first one and we prepare the circuit of the relay R1 so as to exclude the automatic functioning of the start of the movement of the carriage 39.

Thus every time we want to start the machine, we must press the pushbutton PM, and when said machine has completed its sewing cycle, we must press the pushbutton PAT so as to energize the relay R1 and control the starting of the movement of the fabric.

When we want to discontinue said non-automatic cycle of the device, the electromagnetic clutch C can be energized separately in order to bring the carriage 39 to its first position. In order to do this, we must hook the stem 74 to the special tooth 101 by working manually on the pin 80 so that said stem can no more hook with the following expansions 72 of the rod 69 and press the pushbutton PRC for energizing the electromagnetic clutch. When the carriage, moved by said clutch, reaches the vicinity of the expansions 72 of the first collar 71a we repeat the operations described about the return of the carriage 39 to its starting position after the machine has made its last sewing automatic cycle.

FIGURE 1 represents the control board where are visible the control and warning members of the device.

Symbol S2 representing the warning light indicating energization of the circuit at the closing of the general switch Ig does not appear in the description and the drawings because the member represented by it has no vital importance in the functioning of the device illustrated here.

What is claimed is:

1. A sewing machine having a sewing station in combination with a feeding mechanism for feeding selected sections of material to the sewing station of said sewing machine comprising a feeder carriage and means for removably securing the material thereto, a tensor carriage and means for removably securing the material thereto, means for urging the tensor carriage away from the feeder carriage, and means for moving the feeder carriage to successive positions and to maintain it in each of said positions for a predetermined time.

2. A device as in claim 1 further including means for guiding the feeder carriage in a vertical plane.

3. A device as in claim 1 further including means for guiding the tensor carriage in a horizontal plane.

4. A device as in claim 3 further including means pivotally mounting the guide means for pivotal movement in a horizontal plane.

5. A device as in claim 1 wherein the means for urging the tensor carriage away from the feeder carriage comprises a weight and means connecting the weight to the tensor carriage whereby the material is maintained under constant tension between the carriages.

6. A device as in claim 5 further including braking means for braking the weight whereby the speed of the moving weight is gradually reduced to zero.

7. A device as in claim 6 wherein the braking means comprises a cylinder having an open end and a closed end to receive the weight, and a vertical series of apertures in the wall of the cylinder whereby the weight covers the apertures as it drops into the cylinder whereby to gradually increase the pressure of the trapped air.

8. A device as in claim 7 wherein the apertures decrease in size from the open end to the closed end.

9. A device as in claim 1 wherein the means for moving the feeder carriage comprises a source of driving power and clutch means for connecting and disconnecting the source from said carriage.

It). A device as in claim 9 wherein the source of driving power comprises a continuously running electric motor.

11. A device as in claim 1 wherein the maintaining means comprises a rod, a plurality of stops secured to the rod, a latch carried by the carriage, and means for locking the latch on the stops to thereby lock the carriage in each of said positions.

12.. A device as in claim 11 further including means rotatably mounting the rod and means to rotate the rod to withdraw the stops from latching engagement with the latch.

13. A device as in claim 12 wherein the means to rotate the rod comprises an electromagnet having a movable core and means connecting the core to the rod.

14. A device as in claim 13 wherein the means connecting the core to the rod comprises a rack carried by the core and a toothed sector fixed to the rod.

15. A device as in claim 12 further including means resiliently mounting the rod for axial movement, a pair of axially spaced microswitches, and an arm carried by the rod extending between said switches whereby movement of the rod in one direction operates one of the switches and movement of the rod in the opposite direction operates the other switch.

16. A device as in claim 1 further including means for releasing the securing means for securing the material to the feeder carriage after the sewing station has operated on the last section of material.

17. A device as in claim 16 wherein the securing means for securing the material to the feeder carriage comprises a clamping jaw fixed to said carriage and a jaw pivotally mounted on the carriage for engagement with the fixed jaw and wherein the release means comprises a cam fixedly mounted on the sewing machine and means carried by the carriage and operable by the cam for rotating the pivotally mounted jaw away from the fixed )HW.

118. A device as in claim 1 further including means for returning the feeder carriage to the starting position after the sewing machine has operated on the last section of the material.

19. A sewing machine having a sewing station in combination with a feeding mechanism for feeding selected sections of material to the sewing station of said sewing machine to perform a sewing cycle of operations thereon comprising a feeder carriage and means for removably securing the material thereto, a tensor carriage and means for removably securing the material thereto, means for urging the tensor carriage away from the feeder carriage, and means for moving the feeder carriage to successive positions to present the selected sections to the sewing station said moving means comprising a source of power, a drive mechanism for the feeder carriage, clutch means for connecting and disconnecting the power source from the drive mechanism, and means for operating the clutch means, said operating means comprising a rod, means mounting the rod for rotary and axial movement, a plurality of stops adjustably secured to the rod and spaced along the length thereof, the spacing of the stops corresponding to the spacing of the selected sections of material, latch means carried by the feeder carriage for latching engagement with the stops to axially move the rod in one direction, and switch means actuated by the rod upon movement in said one direction to disengage the clutch.

26 A device as in claim 19 further including a second switch means actuated by the rod upon movement in the opposite direction and means responsive to the actuation of said second switch means to operate the sewing station to perform a sewing cycle.

21. A device as in claim 20 further including means o erable at the termination of each sewing cycle to disengage the stop from the latch and engage the clutch to drive the feeder carirage to latching engagement with the next stop.

22. A device as in claim 21 further including means operable at the termination of the last sewing cycle to release the material from the feeder carriage and return said carriage to the starting position for the next series of sewing cycles.

23. A device as in claim 22 further including means operable by the feeder carriage upon return to the starting position to prevent the start of a new sewing cycle.

References Cited UNITED STATES PATENTS Owen et a1 192--116.5 Tyler 26989 Mitchell 18887 Myska 11267 Frey et a1. 192144 Roseridahl 7437 Gardner 112-2 X McGill 112-2 Zeitlin 1122 X Williams 74-816 Reeber et a1 1122 McGill 112-2 Troll et a1. 112-2 10 JORDAN FRANKLIN, Primary Examiner.

I. R. BOLER, Assistant Examiner.

Claims (1)

1. A SEWING MACHINE HAVING A SEWING STATION IN COMBINATION WITH A FEEDING MECHANISM FOR FEEDING SELECTED SECTIONS OF MATERIAL TO THE SEWING STATION OF SAID SEWING MACHINE COMPRISING A FEEDER CARRIAGE AND MEANS FOR REMOVABLY SECURING THE MATERIAL THERETO, A TENSOR CARRIAGE AND MEANS FOR REMOVABLY SECURING THE MATERIAL THERETO, MEANS FOR URGING THE TENSOR CARRIAGE AWAY FROM THE FEEDER CARRIAGE, AND MEANS FOR MOVING THE FEEDER CAR-

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