US2692667A

US2692667A - Sewing machine needle control mechanism

Info

Publication number: US2692667A
Application number: US179866A
Authority: US
Inventors: Walter R Bliedung; Herman C Frentzel
Original assignee: HANSEN GLOVE CORP
Current assignee: HANSEN GLOVE CORP
Priority date: 1950-08-16
Filing date: 1950-08-16
Publication date: 1954-10-26
Anticipated expiration: 1971-10-26

Description

1954 w. R. BLIEDUNG ETAL SEWING MACHINE NEEDLE CONTROL MECHANISM 2 Sheets-Sheet 1 Filed Aug. 16 1950 ii W [0% GINVENTORJ mmwmw Oct. 26, 1954 w. R. BLIEDUNG ETAL 2,592,667

SEWING MACHINE NEEDLE CONTROL MECHANISM Filed Aug. 16, 1950 2 Sheets-Sheet 2 a /(E Call- H 45 lees/57oz Patented Oct. 26, 1954 SEWING MACHINE NEEDLE CONTROL MECHANISM Walter R. Bliedung and Herman C. Frentzel, Milwaukee, Wis., assignors to Hansen Glove Corporation, Wisconsin Milwaukee, Wis., a corporation of Application August 16, 1950, Serial No. 179,866

3 Claims. 1

This invention relates to improvements in sewing machine needle control mechanisms.

Although the invention is susceptible of wider applications, and is not to be restricted, the present improvements find particular utility in connection with the operation of an electric powered sewing machine which may be operated to apply circuitous seams along the marginal portions of shaped fabric or leather pieces, as for the production of gloves. In this particular field, as well as in others of an analogous nature, in order to maintain proper production requirements, it is desirable for the machine operator to be able to control the sewing machine instantaneously and without due efiort or thought, and to also be able to control the position of the needle or tool with respect to the material being worked on,

Along certain portions of the fabric or leather being worked on, the sewing machine may be run at high speed, but when other portions of the fabric are reached, in order to permit the operator to turn the fabric and to sew carefully around curved or eccentric marginal portions of the material, it is highly desirable that the machine be stopped instantaneously and then be susceptible of a slow stitch by stitch operation. The machine should also be susceptible of operation so as to have the needle stop in the fabric to permit the fabric being pivoted around the down engaged needle, or, there may be a high speed operation, according to the requirements, when the fabric is rearranged. The control of the sewing machine should be accomplished with a minimum of attention on the part of the operator in order that he may devote his time to the correct feeding and positioning of the work, leaving both hands free for engaging the fabric.

With the present improved mechanism, therefore, not only can the operator control his machine stitches without taking his hands from the material being worked on, but the improved control mechanism also provides means whereby the operator may automatically position the needle, between sewing operations, so that the material can be properly positioned for the next high speed power sewing, it being noted that formerly it was necessary for the operator at such stages to manually turn the hand-wheel of the sewing machine in order to properly position the needle.

As an example, in the closing operation of a glove there are normally twenty-six stops and starts in the sewing operation. With conventional mechanisms the operator was required to set the hand-wheel during each of these stops for the purpose of positioning the needle and work.

With respect to the enumerated stops it is desirable to have approximately twenty-four of the stops with the needle in the material, while the balance of the stops require that the needle be out of the material. The present invention, in addition to the purposes recited, provides means for automatically stopping the needle in a desired in or out position, thereby saving the tedious hand manipulation of the sewing machine handwheel, speeding up operations, and reducing the fatigue to which the operator may be subjected.

With the above general explanation in mind, it is, therefore, a primary object of the present invention to provide a sewing machine needle control mechanism whereby the speed of operation of the needle or other motor operated tool may be changed from high speed operation to zero speed, and vice versa, and whereby the needle will always be stopped either in or out of the work, according to the desire of the operator.

A further object of the invention is to provide a sewing machine needle control mechanism wherein the position of the needle, either in or out of the work, is selectively accomplished instantaneously and positively and with little effort and thought on the part of the operator.

A further object of th invention is to provide a sewing machine needle control mechanism which will permit on and ofi operation of the machine, which will insure stoppage of the machine with the needle either in or out of the work according to a predetermined plan, and which will furthermore effect decontrol to permit free wheeling of the mechanism if that is desired for any operations, as for threading the needle.

A further object of the invention is to provide a sewing machine needle control mechanism which may be readily built into or associated with a standard electric sewing machine, which is adapted to commercial and large scale operations to maintain high production requirements, which is automatic in its operation, which is strong and durable, and which is well adapted for the purposes described.

In the accompanying drawings in which the same reference characters indicate the same parts in all of the views:

Fig. l is a fragmentary detail sectional view of a sewing machine head wherein the needle reciprocating mechanism has associated therewith and is under the control of a centrifugal switch mechanism, shown in section, with the assemblage also including a solenoid actuated clutch and brake electro transmitter (shown in section) furnishing power to the sewing machine flywheel, said view also including a schematic view of the control treadles and the wiring arrangement;

Fig. 2 is a sectional View taken on line 2-2 of Fig. 1;

Fig. 3 is a sectional View taken on line 3-3 of Fig. 1 and on a larger scale;

Fig. 4 is a sectional view taken on line 5-4 of Fig. 1 and on a larger scale; and

Fig. 5 is a detailed wiring diagram.

The present invention, although not restricted thereto, finds particular utility in connection with the operation of a motor driven sewing machine, such as is used in the commercial production of fabric, leather or specific articles, especially for the manufacture of gloves.

The machine tool, which in this instance is a reciprocating sewing machine needle, through the improved control mechanism is susceptible of instantaneous on and off operation and, additionally, according to any predetermined plan, the machine may be stopped with the needle either in or out with respect to the material being worked on.

To further understand the utility of the present invention in connection with the operation of a powered sewing machine, it should be understood that a normally powered sewing machine is controlled by the operator through the means of a foot treadle, and the latter, through different degrees of movement, effects cessation of the operation of the machine, or operation of the machine at various speeds. In the conventional arrangements the operator must constantly work on the control treadle, which becomes very fatiguing and additionally requires varying degrees of pressure and motion and attention on the part of the operator. In connection with conventional operations it is also a fact that there is a considerable time lag between operations because of the necessity of awaiting the machine actuating elements to actually take hold or effect. Consequently, in conventional electric sewing machines many types of work, and parts of the sewing, require the operator to manually manipulate the sewing machine hand-wheel to perform stitch by stitch operations and to cause the needle to be either in or out of the work so that the material can be positioned or turned for the next power sewing. With the present improvements the cited difficulties are entirely eliminated and on and ofi of the power sewing mechanism is accomplished by an unmeditated feather touch on the control pedal without appreciable time lag, and additionally, the mechanism can always be stopped with the needle either in or out, according to what is desired.

In the present invention, one unit of the improved control mechanism comprises an electrically controlled solenoid operated transmitter, generally indicated by the numeral l5 and directly associated or incorporated with an electric motor 56. The transmitter l5 and motor l6 are preferably in the form of a unit and carry upwardly directed brackets I'I merging into a horizontal plate [8 whereby the unit may be bolted or otherwise secured to the table portion IQ of an electric sewing machine 20.

The outwardly extending shaft of the electric motor is is designated by the numeral 2| and the central hub portion of a flywheel 22 is keyed to the enlarged inner end portion of said motor shaft 2!. The outer end of the motor shaft is reduced and carries fast thereon a circular driving solenoid 23 whose flanged inner end portion is rigidly attached to the flywheel 22 by screws 24. A clamping stud or screw 25 extends centrally axially into the solenoid 23 to abut the outer end of the motor shaft portion thereadjacent. Carried fast by the outer peripheral portion of the solenoid 23 is a running clutch 2% of annular formation. Set into the opposite faces of a metallic plate 40 and of magnetic material, are rings of any suitable clutch fabric or friction material 28. In the outer face of the flywheel 22, against a ring of insulating material 29 there is secured a copper ring 3%. Said copper ring is electrically connected to the windings 3! of the solenoid 23 by means of wiring. Current is conducted to the copper ring as by a brush 33 mounted on the inner end of an adjustable stem 3 1 which is threaded through a lower frame arm 35, being maintained in its adjusted position by a clamping nut 36.

The frame portions H and 35 are shaped to form a separable circular bearing enclosing the sleeve portion 37' of a brake solenoid 3?. Within the sleeve portion 3'! there are roller bearings 38 to facilitate turning movement of a pulley shaft 39 which extends axially through the sleeve portion 3i" and through the central portion of the solenoid 31. The innermost end portion of the pulley shaft 39 has splined thereto the hub of the metallic plate til, previously mentioned. The outermost end portion of the shaft 39 has fast thereon a pulley M which drivingly carries a belt it. A ring-like brake clutch 42 of split formation, and similar to the clutch 26, is in screw threaded engagement with the outer periphery of the solenoid 31. Electrical current is conducted to the windings 43 of the solenoid 3'? by a suitable circuit wire M1, and it may also be stated that the brush 33 carries a circuit wire :35. Circuit wire A5 is connected directly with a terminal on a suitable treadle switch it which is shown schematically in Fig. 1 and circuit as ultimately connects with the other terminal on said treadle switch. In practice, this treadle switch is manipulated by the foot of the machine operator and controls instantaneous off and on or running and stopping of the machine mechanism associated with the improved solenoid operated transmitter.

From the description thus far given it should be evident that the shafts 2! and 39 are separated and that the former has fast thereon the solenoid 23, while the pulley shaft 39 is free to turn within the hub portion of the solenoid 3?, which is stationary. However, the metallic plate id is splined to the inner end of the pulley shaft 39 so as to be selectively engageable with either the face portion of the solenoid 23 or the face portion of the solenoid 3'8, depending upon which is energized. Consequently, the splined mounting of the disc 40 is such that the disc may have minute axial movement on the shaft 39 for the purpose of being pulled against which ever solenoid is energized.

The sewing machine 26 to be associated with and controlled by the improved solenoid operated transmitter has a driving sheave or pulley H to which the belt H3 extends. The sewing machine is of the type which should operate, when, on at high speed, and then be susceptible of immediate cessation, under the control of the operator with the sewing machine needle either in or out of the work, according to whatever is desired. It will, therefore, be appreciated that for on and off operation of the sewing machine, by means of the transmitter 15, if the operator imparts pressure to the treadle sufficient to close the contact element of the switch 46 with the terminal which carries the circuit wire 45, the solenoid 23, through the coil 3|, will be energized and will magnetically attract to its face the metallic plate 40, the latter being disengaged from the solenoid 37, because under these conditions, the last-mentioned solenoid is deenergized. Engagement between the revolving solenoid 23 which is driven directly from the electric motor l6, and the me tallic plate is effective to rapidly revolve the pulley shaft 39 and through the belt 1 l motion is transmitted to the pulley l l of the Sewing machine.

When it is desired to stop or brake the sewing machine the operator then manipulates the treadle switch in a manner to open the circuit through the wire 45 and to make the circuit through the wire 44, thereby energizing the solenoid 31 and deenergizing the solenoid 23. The result is that the metallic plate 40 is immediately engaged with the solenoid 3'! and rotation is instantly arrested through the braking material on the adjacent face of the plate 40.

The electric motor 16 carries conventional circuit wires 48 which may be extended to the source of electrical current and it should be observed that a circuit wire d9 connects with one of the terminals of a decontrol switch 1%, later to be described, which also extends to the power supply through a rectifier 10!. The same is true of a circuit wire 8 which has its inner end grounded on a metallic frame portion of the transmitter [51, as at 42.

While an electric motor I 6 has been illustrated in association with the transmitter l5, it'should be understood that the shaft 2! may be driven from any convenient power source.

Another unit of the improved control mechanism comprises a centrifugal switch device shown in section in Fig. l and indicated generally by the numeral 56. This centrifugal switch assembly is supported by an upstanding bracket arm 5i whose base portion is bolted or otherwise secured to the top surface of the sewing machine table portion [9. It will be observed that the sewin machine pulley H is formed on its outer face with a dished extension H which receives a disc 52 which is secured to the pulley l I by bolts 53 so as to turn therewith.

The disc 52 has an outwardly projecting axial hub portion 54 and radially outwardly of said hub portion the disc carries protuberances 55 on which are pivotally mounted governor weights 56.

It was previously noted that the sewing machine pulley wheel II is positively driven by the belt Iii. As the pulley H accelerates in speed the governor weights 56 pivotally move, by centrifugal force, in a direction so that the fingers 55, formed on the inner ends of the governor weights, move toward the left (relative to Fig. 1) and thereby impinge against the inner annular shoulder on a sleeve 51, which axially surrounds the hub portion 54 of the disc 52. Confined within a shouldered recess therefor in the sleeve 5'! is a coiled spring 58 and the action of the governor weights described and the axial movement of the sleeve 5'! compresses said spring 58 causing a disc cam is to move axially toward the left relative to Fig. 1 and away from switch plungers which are loosely mounted through bores therefor in a stationary guide block 6!. It should be observed that the disc cam 59 has a sleeve portion slidably embracing the hub portion 54 of the disc 52 inwardly of the sleeve 51. Enough axial movement is afforded the disc cam 59 and its sleeve so that the disc cam will not contact the ends of the switch plungers 60 during running operation, thus preventing wear on both the cam and on the plungers, and permitting the switch plungers til to be in released position and thereby holding switches 62 and 62' in circuit breaking position when switch 46 is released or in its stop position.

In the specific embodiment illustrated, the machine whose tool is to be controlled, is the power operated sewing machine 20 having a needle 63 depended from a vertical reciprocatory needle shaft 64. The latter, as is conventional, carries a block engaged by a cam 86 on the inner end of a revoluble shaft 61, the latter carrying fast at its other end the sewing machine drive pulley H which, as was previously mentioned, is engaged by the driven belt l0. Not only does the sewing machine needle control mechanism provide means for instantaneously stopping or starting the reciprocations of the needle 63, but the unit 50 provides positive means for insuring the stoppage of the needle 63 either in its down position with respect to the work on the table I!) being sewed, or in an up, out-of-the-work posi tion. The latter are the functions of the

switches

62 and 62 whose wiring arrangement in the system will be apparent from Figs. 1 and 5. According to the particular circuit arrangement, the switch 82, for instance, controls the needlein stoppage of the machine, and the switch 62 controls the needle-out position of stoppage.

With particular reference to the schematic portion of Fig. 1, wherein the treadle switch 46 is shown which is adapted to be engaged by the foot of the machine operator, if this treadle switch which controls the running and stopping of the machine is released, the circuit to the clutch solenoid 3| is opened and the circuit to the magnetic brake solenoid 43 is closed through circuit wires 44, the normally closed contacts of

switch

62 or 62, wires 44 or 44 (depending on the condition of switch 62 or 62), and then to the proper terminal of switch 58. Then, the driving disk 40 of the unit I5 is removed from contact with the clutch member 26 and is firmly engaged with the magnetic brake element 42. The operation of the brake causes rapid deceleration of the driven pulley H on the sewing machine shaft 6?, which, upon coming to rest, permits the governor spring 58 to thrust the disc cam 59 of the assemblage 53 in an axial direction against the face of the block 6|. Should the driven pulley ll stop rotation in a pre-selected position, the machine remains inoperative until either the run-stop treadle switch 46 or a needle up-or-down switch 68 is operated.

As was previously brought out it is, of course, a specific object of the invention to provide means for positively determining the position of the sewing machine needle 63 (either in or out of the work) according to a predetermined selection, when the machine stops. This is the function of the

switches

62 and 62 controlled by the governor operated cam disc 59. It is possible that the normal momentum of the machinery might, when the sewing machine stopped, cause the needle to be out of the work, for instance, although the operator desired the needle to stop in its down, in the work position. The switch plungers 60 are loosely mounted through the guide block El and the upper plunger 6?] operates switch 62 while the lower plunger 60 operates switch 62'. If the disc cam 59 is forced toward the right in Fig. 1 and is in the position shown in Figs. 1 and 4 it will, of course, actuate the upper switch plunger 69 for the switch 62 thereby deenergizing the brake solenoid Q3 and energizing the clutch solenoid 3!. This causes rotation of the pulley ll under two conditions. Should the cam 59 be in such a position that the upper plunger 69, for instance, of switch 62 is about to be disengaged by said cam, then as soon as this occurs there is an energization of the brake solenoid 43 and a deenergization of the clutch solenoid 31. This satisfies the condition imposed by the predetermined position of the needle up or down treadle 88. On the other hand, should the advance portion of the cam 59 just have engaged and depressed the upper plunger 68, then the clutch solenoid 3! will be energized and the hub 54 again rotates with cam 59 until the speed of the pulley II is of such magnitude as to move the centrifugal weights 55 to shift the cam 59 to the left. At this point the brake solenoid 43 is again energized, causing deceleration of the machine, so as to stop the needle We in the desired position. The purpose of the centrifugally controlled switches 62 and 82 is to prevent an override of the position desired, as the solid cam face 59 is, at times, a large percentage of the complete periphery.

If the switch 68 is actuated rapidly the operator of the machine may take a power driven single stitch. or inching operation for each complete up and down manipulation of said treadle switch 68. With reference to the schematic portion of Fig. 1 and also with reference to Fig. 5, the switch It!) is a free wheeling treadle switch which opens the circuits to both the clutch and brake solenoids, thereby allowing the machine to be indexed by hand for needle threading or other purposes.

The operation of the improved mechanism is as follows:

With the electric motor 16 in operation, initially all of the switches in the system except the run-stop switch 45 are in normal released positions. The brake solenoid 43 is energized through the circuit from the source or rectifier it! through contacts C-NC (Fig. of the run-stop treadle switch 46 and then through contacts C-NC of the needle up and down treadle switch 58, and finally through contacts C-NC of the control switch 62 and through the circuit wires M or M" and then wire 44 to the brake solenoid 43.

A foot manipulation of the run-stop treadle switch 46 energizes the clutch solenoid 3! from the rectifier or source, through contacts C-NO of the run-stop treadle switch at (Fig. 5) and circuit wire 45. As the machine accelerates, both control switches 62 and 52' close their C-NC contacts. The release of the run-stop treadle switch as functions to close contacts C-NC thereof whereby an energization of the brake solenoid 43 takes place through either the control switch '62 or the control switch 52, depending upon the particular position of the ne dle up or down treadle switch 68 and circuit wire 44. When the machine comes to a stop, the axial motion of the disc cam 59 functions to close either the switch 62 or the switch 62. If the machine stops in a position which would have the needle in an undesired position according to the work, the circuit to the brake solenoid d3 is then interrupted by either of the control switches 60 or 62 through circuit 34 and there is a temporary energization of the clutch solenoid 3| until such time as the desired position is reached for the stopping of the needle (either up or down, as pre-selected) By particular reference to Fig. 5 and also referring to the schematic portion of Fig. 1, it should be evident that the electrical system includes a pair of inter-related electrical circuits. One circuit, which may be termed the control or non-running circuit includes and is under the control of the main stop and run switch it, and additionally includes the needle up and needle down switches 62 and 62. The other circuit which is inter-related with the first mentioned circuit may be termed a running circuit and besides the main switch We also therein, said running circuit includes the clutch and brake solenoids 3i and t3. Said running circuit is, of course, affected by the first mentioned control circuit when it is necessary for the machine to readjust itself for a predetermined selected needle position, when the machine stops, as previously described.

From the foregoing it should be evident that the unit 50 associated with a machine such as a sewing machine, which also has incorporated therewith the electircally controlled solenoid operated transmitter !5, makes it possible, through selected operation of the needle up or down treadle, to have the machine positively stop with the needle in a predetermined up or down position. These results are obtained from the governor weights 56 which are effective to axially move the sleeve portion of the cam disc 5% whereby, during operation, said sequence cam disc 59 is moved away from the switch plungers, whereby the brake circuit is immediately completed when the machine operator lifts his foot from the run-stop treadle switch 46. A mechanism such as a power sewing machine equipped with the improved control mechanism can be operated with a minimum of attention on the part of the operator leaving his hands free for feeding and positioning the work. The control mechanism also has the other advantageous functions heretofore mentioned including free-wheeling and the change in the speed of operation of the tool from. high speed to zero speed, and vice versa.

The improved sewing machine needle control mechanism is furthermore of relatively simple construction and is well adapted for the purposes set forth.

What is claimed as the invention is:

1. A control apparatus for an automatic tool, comprising a driven shaft connected to said tool for operating the latter, a solenoid operated stop and go transmitter operatively connected to said shaft to drive it, and means for predetermining either of two separated positions of rest of said tool upon cessation of operation of the transmit ter, said latter means including first and second tool rest position control switch members electrically associated with said transmitter, manually operated means electrically associated with said first and second tool rest position control switch members for selecting one of the other of said last-mentioned switches for operation, and a centrifugal device carried by said driven shaft for operating the one of said selected position control switch members.

2. In combination, a driven shaft for moving a tool, an electrically operated power transmitter operatively connected to said shaft, a pair of electrical shaft position switches, one of said position switches determining one position of rest of said shaft upon controlled cessation of operation of the power transmitter and the other of said position switches determining another position of rest of said shaft upon controlled cessation of operation of the power transmitter, a centrifugal device carried by said driven shaft for automatically operating one or the other of said position members, a running electrical circuit including said transmitter, a control electrical circuit connected with said running circuit and including said position switches, a main control switch included in both of said circuits, and a manual switch included in said control circuit, selective operation of said manual switch determining operation of a predetermined position switch.

3. A control apparatus for an automatic reciprocatory tool, comprising a driven shaft connected to the tool for reciprocating the latter between extreme in and out positions, a solenoid operated stop and go transmitter operatively connected to said shaft to drive it, and means for predetermining a position of rest of said tool in either its in or its out position upon cessation of operation of the transmitter, said latter means including a tool in switch and a tool out switch, both of which are electrically associated with said transmitter, manually operated means electrically associated with said, switches for selecting one or the other of the same for operation, and a centrifugal device carried by said driven shaft for operating the selected one of the aforesaid switches.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,253,927 Molyneux Mar. 12, 1918 1,392,696 Molyneux Oct. 4, 1921 1,702,662 Morril Feb. 19, 1929 1,993,413 Mellon Mar. 5, 1935 2,259,574 Lillquist Oct. 21, 1941 2,288,135 Hoza June 30, 1942 2,338,975 Schumacher Jan. 11, 1944 2,354,010 Groene et al. July 18, 1944 2,470,103 Lochman May 17, 1949 2,528,316 Mayo Oct. 31, 1950