US1756655A - Thread-controlling mechanism for sewing machines - Google Patents

Description

April 2 3 J. R. MOFFATT 1,756,655

THREAD CONTROLLING MECHANISM FOR SEWING MACHINES Filed Aug. 29. 1928 Patented Apr. 29, 1930 ice JAMES R. MOFFATT, OF CHICAGD, ILLINOIS, ASSIGNOR '10 UNION SPECIAL MACHINE COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS THREAD-CONTROLLING MECHAN'ISM FOR SEWING MACHINES Application filed August 29, 1928.

The invention relates to new and useful improvements in thread controlling mechanisms for sewing machines, and more particularly to the thread guiding mechanism used in connection with a rotary thread controlling element. 7

An object of the invention is to provide a thread guiding mechanism used in conjunction with a rotary thread controlling element having laterally projecting thread engaging cam faces, which thread guiding mechanism includes open thread eyes so that said thread guides may be readily threaded without mov ing the same to render them accessible.

A further object of the invention is to provide a thread guiding mechanism of the above type wherein the thread guides and the cast-oft are all mounted on one supporting member adapted to be adjusted in a direction circumferentially of the axis of rotation of the thread controlling element.

In the drawings Figure 1 is a plan view of a portion of a sewing machine embodying the improvements.

Fig. 2 is a sectional view on the line 2-2 through a portion of the thread controlling element and showing the supporting bracket for the thread guides and cast-ofl in edge view.

Fig. 3 is a sectional View on the line 33 of Fig. 1.

Fig. 4 is a perspective view of the supporting segment for the thread guides showing thethread guides and the cast-0E and stripper mounted thereon.

The invention is directed to a thread controlling mechanism of the type wherein there is a rotating thread controlling element having laterally projecting cylindrical flanges radially spaced from each other and with their free edges shaped to provide thread take-up cams. Associated with this thread controller is a thread guiding mechanism which includes an outer thread guide located outside of the periphery of the thread controlling element, and an inner thread guide located inside of the periphery of the flanges. The inside thread guide is carried by a segment bracket and is provided with a project- 50 ing arm on which the outer thread guide is Serial No. 362,803.

mounted. On the arm carrying the outer thread guide the cast-off and thread retainer are mounted. Both the inner and the outer thread guides include eyes with a slot leading therefrom andthe face of the supporting memher for each thread guide is curved so that when the thread is laid against said curved faces and drawn on it will slide along both of the curved faces through the slots and into the eyes. Thus it is that the thread guiding mechanism is self-threading. I

Referring more in detail to the drawings, the invention is shown as applied to a sewing machine having a cylindrical supporting member 1 in which is mounted a rotating shaft 2. This rotating shaft-2 carries the rotating thread controllingelement 3. Said rotating thread controlling element 3 is provided with an outer cylindrical flange 4 and an inner cylindrical flange 5. These flanges are radially spaced from each other. The free edges of the flanges are cam shaped and these are the thread controlling cams which in succession engage the threads for taking up and giving up said threads. is mounted on the shaft and this sleeve is held from rotation with the shaft so that it is stationary. Attached to this sleeve is a segment bracket 7, which is secured to the sleeve by a screw 8 passing through a slot in the bracket and threaded into the sleeve. Thus it is that the segment bracket may be ad justed circumferentially on the sleeve about the center of the shaft;

Projecting outwardly from this segment bracket 7 is an arm 9. This arm 9 is provided with a thread eye 10 and a slot 11 leading to the eye. There is also a curved surface 12. Just beyond the eye from the curved surface 12 there is a shoulder 13. The thread engaging curved face 12 will slide along the same and pass through the slot 11 into the thread eye 10. Also attached to this arm 9 is a second arm 13*. This arm projects overthe rotating controlling element while the arm 9 is inside thereof so that the thread eye 10 is radially disposed. within the periphery of the inner thread controlling flange 5. The arm 18 is provided with a curved face 14 which leads into an A sleeve '6- gles to the axis of the shaft.

between the nipper springs 17.

guide, and this thread eye is located beyond the periphery of the outerthread controlling flange 4; The thread is led from the supply through a guiding passage 16 and thence The thread is indicated at Z in the drawings. After the thread leaves the nipper springs ifit is placed against the curved faces 12 and 14 and drawn toward the front of the machine it will slide along these curved surfaces and enter the eyes 10 and 16. Thus it is that the thread guides o are self-threading as all that is necessary is to lay the thread against the curved faces and pull on it and it will enter the eyes.

Attached to the arm 13 is a forwardly pro-- jecting member 18, which is provided with a straight face 19 lying in a plane at right an- Also carried by this projecting member 18 is a cast-off arm 20, which lies in the space between the cylindrical flanges controlling the thread This cast-off member engages the thread and casts it off from the cam faces, while the retainer 19 puts a slight drag on the thread and retards the thread as it is given up to the stitching element with which said controller is associated. This thread controller'with its cast-off and retainer per se form no part of the present invention. They are similar in mode of operation to the cast-off and retainer disclosed in my co-pending application Serial No. 130,954, filed August 23, 1926. The present invention is directed particularly to the manner of mounting the thread guides and the construction thereof whereby they are self-threading. 7

It is obvious that minor changes in the details of construction may be made withoutdeparting from the spirit of the invention as set forth-in the appended claims.

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent, is

1.. A thread controller for sewing machines comprising a rotating shaft, a thread controlling element mounted on said shaft and having av laterally projecting flange, thread guides located Within and withoutthe periphery of the flange, an arm for each thread guide, said arms extending laterally beyond the flange and connected at their outer ends, each arm having a curved face leading through a slot to a guide eye forming. the thread guide, and means for supporting said arms. 7 V

2. A thread controlling for sewing machines comprising a rotating shaft, a thread controlling element mounted on said shaft and having laterally projecting cylindrical flange, thread guides located within and without the periphery of the flange, an arm for each thread guide extending laterally be- 'ycnd the flange and connected at their outer ends, and a stationary supporting bracket to which the arm of the inner thread guide is connected, said arms having curved faces leading through slots to the guide eyes form ing eyes forming the thread guides. I

3. A thread controller for sewing machines comprising a rotating shaft, a thread. ccntrolling element mounted .on said shaft. and having a laterallyprojecting cylindrical flange, thread guides located within and with out the periphery-cf the flange, anarm foreach thread guide extending laterally beyond the flange and connected at their outer ends, a stationary supporting bracket to which the arm of the inner thread guide; is connected, said,

arms having curved faces leading through slots to the guide eyes forming the thread guides, a member projecting from the arm carrying the outer thread guide, said member being disposed. relative to the flange of the thread controlling element and shaped so as to provide a cast-off for casting the thread ofl" from the controlling cam formed on said flange, and a retainer for retaining the thread after it is cast from the controllingcam.

4. A thread controller for sewing machines comprising a rotating shaft, a threaded controlling element secured to the shaft and having radially spaced laterally projecting cylindrical flanges, thread guides located with in and without the, periphery of the flanges,

a stationary sleeve on the shaft extending underneath the flanges, a segmental bracket see cured to said stationary sleeve, an arm for the inner thread guide vrigidlyconnectedto said bracket, and an arm for the outer thread guide attached to the arm for the inner thread guide ata'point beyond saidlflangeasaid arms having curved faces leading through slots to eyesforming the thread guides whereby said thread guides are self-threading.

' 5. A thread controller for sewing machines 7 comprising a rotating shaft, a thread controlling element secured to the shaft and having radially spaced laterally projecting cylindrical flanges,.thread guides located within and without the peripheryyof theflanges, a stationary sleeve on the shaft extending under-, A

neath the flanges,a segmental bracket secured to said stationary sleeve, an arm for the inner thread guide rigidly connected to said bracket, anarm for the outerthread guide attached to the arm forthe inner thread guide at a point beyond said flanges,.said arms having curved faces leading through slots to eyes forming the thread guides whereby said thread. guides are self-threading and, a member secured to the arm carrying the outer thread'guide, said member having a portion projecting between said flanges and provided with an inclined face for stripping the thread from the take;

up cams formed on said flanges.

6. A thread'controller. for sewing machines comprising a rotating shaft, athread controlling element secured to the shaft and having radially spaced laterally projecting cylindrical flanges, thread guides located Within and Without the periphery of the flanges, a stationary sleeve on the shaft extending underneath the flanges, a segmental bracket secured to said stationary sleeve, an arm for the inner thread guide rigidly connected to said bracket, an arm for the outer thread guide attached to the arm for the inner thread guide at a point beyond said flanges, said arms having curved faces leading through slots to eyes forming the thread guides Whereby said thread guides are self-threading, and a member secured to the arm carrying the outer thread guide, said member having a portion projecting between said flanges and provided with an inclined face for stripping the thread from the take-up cams formed on said flanges, said member also having a thread retaining face adapted to cooperate with the flanges in the retaining of the thread after it is cast from the take-up cams.

In testimony whereof, I affix my signature.

JAMES R. MOFFATT.

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