US2321550A - Rotary take-up for sewing machines - Google Patents

Description

June 8, 1943- H. N. KARR ET AL ROTARY TAKE-UP FOR SEWING MACHINES Filed Nov. 5, 1940 Pi l HE:

avwm w'o and enry J1. afar) .Pobert wszewart Patented June 8, 1943 ROTARY TAKE-UP FOR SEWING MACHINES Henry N. Karr and Robert W. Stewart, Bridgeport, Conn., assignors to The Singer Manufacturing Company, Elizabeth, N. J., a corporation of New Jersey Application November 5, 1940, Serial No. 364,372

This invention relates to rotary take-up mech- 7 Claims.

anisms for sewing machines and more particularly to devices for preventing abnormal winding of thread about the thread-engaging element or elements of a rotary take-up, in the event of thread breakage.

The present invention is in the nature of an improvement in the thread-severing device for rotary take-ups of the U. S. patent of S. Zonis, No. 2,263,533, Nov. 18, 1941, and has for its object to prevent accidental severing of-the thread by said severing device in the normal handling of the thread by the take-up mechanism.

The invention. consists in the provision of a guard disposed with respect to a thread-severing device, associated with a rotary take-up, to control the thread in a manner insuring that the thread is free from severing engagement by said severing device in the normal handling of the thread by the take-up mechanism. A preferred embodiment of the invention is illustrated in the accompanying drawing, in which:

Fig. l is a front end elevation of the bracketarm head of a sewing machine containing the present improvement. Fig. 2 represents an enlarged section, on substantially the line 2-2 of Fig. 1, of the rear take-up device of the machine. Fig. 3 is a view similar to Fig. 1 of the take-up devices, the thread-engaging and -severing elements being shown partly in section, and illustrating in dotted lines an abnormal thread position guarded against by the present improvement. Fig. 4 represents an enlarged vertical section of the face-plate of the machine, the section corresponding to that of Fig. 2.

The sewing machine illustrated in the drawing has a frame including a bracket-arm terminating at its free end in a head 10. Journaled for vertical reciprocation in the bracket-arm head is a needle-bar l l, carrying at its lower end a needle l2, said needle-bar being reciprocated by any usual or suitable actuating connections with a horizontally disposed main actuating shaft l3. Also journaled for endwise vertical movements in the head I0 is the usual spring-depressed presserbar M, to the lower end of which is attached the Presser-foot l5 opposed to the work-advancing feed-dog l6 of the usualdrop-feed type. V

The main-shaft I3 carries a take-up disk I] at the bracket-arm head end of said shaft. Spaced from and secured to the take-up disk H, by a pair of radially equidistant thread-engaging studs or elements I8, is a fiat thread-confining ring l9. Being carried by the main-shaft l3 for rotation therewith, the take-up elements l8 perform one rotation for each complete reciprocation of the needle I2 and in a counterclockwise direction when viewed as in Fig. 1 of the drawings.

The rear or.supplemental take-up is carried by a rotary shaft 20 disposed in paraljellsm with the main-shaft l3, said shaft 20 being preferably actuated in any usual or suitabld manner to perform two rotations for each rotation of and in the same direction as the main-shaft I3.

Carried by the rear take-up shaft 20 for rotation therewith is a disk 2i having"the outer face thereof disposed in substantially the same vertical plane as the front take-up disk 11. A flat threadconfining ring 22 is secured in spaced relation to the take-up disk 2!, for rotation therewith, by a pair of adjacent and radially equidistant studs or thread-engaging elements 23 which are preferably grooved as illustrated in Fig. 2 of the drawing. The face of the disk 2| proximate to the ring 22 is centrally provided with an annular recess 24.

Detachably secured to the front end of the bracket-arm head I!) of the machine frame is a face-place 25 provided upon the outer face thereof with stationary block 26 disposed between the iron and rear take-up elements, said block 26 having an upwardly open slot 21 affording clearancefor the needle-thread N extending from one to the other of the take-up elements. Attached to the block 26, by screws 28, is a flanged guard-plate 29 spaced from the take-up'rings l9 and 22. The guard plate 29 is suitably recessed to provide clearance for the shank 30 of a stationary thread-severing member 3! secured upon the block 26 by a screw 32 for adjustment endwise of the shank 30.

The shank 30 of the thread-severing member extends across the outer face of the take-up ring 22 in spaced relation thereto, and the threadsevering member 3| is bent inwardly from its shank so as to be disposed in proximity to and within the orbital path of rotation of the takeup elements 23. The severing member 3| extends substantially normal to the plane of the orbital path of the elements 23 and terminates at its free end within and in close proximity to the inner wall of the take-up disk recess 24. The severing member 3| is therefore disposed in the plane containing the orbit of rotation of the take-up elements 23.

Cooperating with the stationary thread-severing member 3| in severing thread when wound abnormally about the take-up elements 23, as may occur in the breakage of the thread, is a movable thread-severing member 33 having a cutting edge 33'. The thread-severing member 33 is carried by the take-up disk 2| forfrotation therewith, said member 33 being preferably disposed between the take-up elements 23. The construction and function of the cooperating thread-severing members 3| and 33 is substantially the same as more fully disclosed in the Zonis Patent No. 2,263,533 hereinbei'ore mentioned.

In general, it may be stated that should the thread N start to wind about the elements 23, in the event of thread-breakage, the. thread necessarily also starts to wind about the movable severing member 33 which is disposed between said elements. The stationary and movable severing members 3| and 33 are so disposed relatively as to sever thread passed between said members. Consequently, should the thread abnormally start to wind about the take-up elements 23, and be thereby passed between the severing-members 3| and 33, the thread will be immediately severed by said severing members, thereby preventing further winding of the thread about the elements 23.

Under'certain thread-handling conditions, it may happen when the elements I! and 23 are together giving up slack thread, that athreadloop or bight shown in dotted lines in Fig. 3 of the drawing may be formed between the movable severing member 33 and the stationary severing member 3|, at the time when the member 33 is approaching the member 3|. Should this loop of thread be carried between the severing members by the thread-handling mechanism the thread will be accidentally severed uuder normal sewing conditions.

To insure against occurrence of the described accidental severing of the thread, there is now provided a thread-guard member or finger 34 disposed adjacent and in advance of the stationary thread-severing member 3| in the direction of approach of the movable severing member 33 to the member 3|. The guard-finger 34 is bent to extend laterally from its shank 35 which is suitably attached to the inner face of the take-up guard-plate 23; the guard-finger 34 preferably extending from its shank in a direction substantially normal to the plane and within the orbital path of rotation of the movable severing member 33 in proximity yto said orbital path. The free end of the guard-finger 34 preferably terminates in the take-up disk recess 24 in proximity to the inner wall of said recess, to

insure that the thread cannot pass between the end of the guard-finger and the take-up disk 2|. The guard-finger 34 thereby intersects the plane of rotation of the take-up-elements 23.

As illustrated in Fig. 3 of the drawing, the guard-finger 34 serves to intercept and detain the thread which, under normal sewing conditions, overlies the stationary severing member 3| and the take-up elements 23 when the movable severing member 33 is approaching the stationary severing member 3|. Thus the guard-finger serves normally togprevent engagement of the thread by the thread-severing members and thereby obviate accidental severing of 'the thread during the stitching operation of the machine.

Having thus set forth the nature of the invention, what We /claim herein is:

1. In a sewing machine having a rotary-thread take-up element, and thread-severing means disposed in the plane of rotation of said take-up element, the improvement which consists in the -provision ,of a guard-member disposed in the plane of rotation of said take-up element in position to intercept and detain the thread from thread-severing engagement by said means in the normal handling of the thread by said take-up element.

2. In a sewing machine having a plurality 0! thread take-up elements rotatable about a common' axis, a'movable thread-severing member supported between said take-up elements for rotation therewith, and a complemental stationary thread-severing member disposed within the orbit of rotation of said movable thread-severing member, one of said thread-severing members having a cutting edge disposed for co-action with the other thread-severing member in the plane of rotation of said take-up elements, the improvement which consists in the provision of a stationary guard-member disposed in the path of the thread within the orbit of rotation of said movable thread-severing member in position normally to intercept and detain the thread from thread-severing engagement by said members.

3. In a sewing machine having a plurality of thread take-up elements rotatable about a'common axis, a stationary thread-severing member. and a movable thread-severing member supa ported'between said take-up elements for rotation therewith and for co-action with said stationary member in severing thread abnormally wound about said elements, one of said threadsevering members having a cutting edge disposed for co-action with the other thread-severing member in the plane of rotation of said take-up elements, the improvement which consists in the provision of a stationary guard-member disposed in the plane and within the orbit of rotation of said movable thread-severing member in position normally to intercept and detain the thread from thread-severing engagement by said members,

4. In a sewing machine having a rotary thread take-up element, thread-severing means disposed to sever thread abnormally wound about said take-up element, and a stationary guard-plate for said take-up element, the improvement which consists in the provision of a thread-controlling guard-member extending from said guard-plate across the plane of rotation of said take-up element in position to oppose movement of the 557severing members disposed within the orbit and in the plane of rotation of said take-up element for coaction in severing thread abnormally wound about said element, of a guard disposed within the orbit and in the plane of rotation of said take-up element for opposing movement into the range of action of said severing-members of thread given up by said take-up element during the normal stitch-forming cycle. 1

6. In a sewing machine, the combination with a thread take-up element rotatablein an orbital path, and means efiective in a substantially constant position of said element in said orbital path for severing thread abnormally wound about said element, of a' stationary guard-member disposed within said orbital path in advance of the threadsevering position of said means in the direction from which said element approaches said position,..for opposing movement into the range of action of said severing means of slack thread normally given up by said take-up element.

'7. In a sewing machine, the combination with a rotary thread take-up element, a movable thread-severing member rotatable in an orbital path with said take-up element, and a. stationary thread-severing member complemental to said movable severing member in severing thread abnormally wound about said take-up element, of a stationary guard-member disposed within said orbital path adjacent and in advance of said stationary severing member in the direction from which said movable severing member approaches said stationary member, for opposing movement into the range of action of said severing members oi thread normally given up by said take-up element.

HENRY N. KARR.

ROBERT W. STEWART.

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