Patent US3683832A successfully refreshed from Google Patents.
US3683832A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thread control device for sewing machines
Assignee: Union Special Machine Co
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Filing: 1970-09-04
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Granted: 1972-08-15
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Expires: 1990-09-04
Abstract
Abstract An improved thread control mechanism for sewing machines adapted to minimize breakage and entanglement of the needle thread in a two-thread sewing machine, and which insures the formation of a uniform and desirable line of stitching at high speeds of operation. It is particularly advantageous in connection with a lockstitch sewing machine, which at one stage in a cycle of operation of the machine must subject said thread to a quick take-up action when a loop of the thread has been passed around half of the circumference of a bobbin case. The improved mechanism eliminates the need for a coiled check spring which heretofore has been provided to present an arm in the path of movement of the thread after it leaves a thread tensioning device. By eliminating the need for the check spring, the extent of movement of a thread eyelet at the outer end of a take-up lever is reduced, from the extent that was required in prior constructions involving a check spring. A plurality of cams are provided on a shaft which is rotated at the same speed as the main drive shaft of the sewing machine. These cams act upon different portions of the needle thread as the latter passes through a succession of eyelets provided on certain prongs of rockable members. Normally these members are retained in an active position, but they are shifted to an inactive position upon the lifting of the pressure foot. The thread control means of the present invention exercises the desired control over the needle thread when the machine is used on a variety of types of work which have normally, heretofore, required special adjustments and even changes in the mechanism when variations in the thickness and the nature of the work pieces being dealt with are involved.
Inventors
- 👤 Edgar Schoij
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 20:59
CPC Classifications
D; D05; D05B; D05B51/00
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
118 words
Sewing apparatus comprising a machine having a reciprocatory needle bar carrying a needle, cooperating stitch forming means, a main drive shaft, connections from said shaft for reciprocating said needle bar and driving said cooperating stitch forming means, a thread supply means, means for controlling the delivery of thread from said supply means to said needle comprising a control shaft rotated in synchronism with said drive shaft, clamping means operated by said control shaft for gripping the thread and locking it against movement to prevent additional thread being delivered from the supply to the needle from the time the thread begins to be pulled up by the cooperating stitch forming means until the time that the stitch is set.
Claim 2
Dependent Claim
118 words
Sewing apparatus comprising a machine having a reciprocatory needle bar carrying a needle, cooperating stitch forming means, a main drive shaft, connections from said shaft for reciprocating said needle bar and driving said cooperating stitch forming means, a thread supply means, means for controlling the delivery of thread from said supply means to said needle comprising a control shaft rotated in synchronism with said drive shaft, clamping means operated by said control shaft for gripping the thread and locking it against movement to prevent additional thread being delivered from the supply to the needle from the time the thread begins to be pulled up by the cooperating stitch forming means until the time that the stitch is set.
Claim 3
Dependent Claim
36 words
In sewing apparatus as set forth in claim 1, wherein said clamping means for locking the thread in position comprises cam means rotated by the control shaft in timed relation to the cooperating stitch forming means.
Claim 4
Dependent Claim
52 words
In sewing apparatus as set forth in claim 1, wherein there are means also operated by said control shaft positioned between the clampIng means and the thread supply for pulling off a predetermined amount of thread from the supply during the period in which the thread is gripped by the clamping means.
Claim 5
Dependent Claim
129 words
Sewing apparatus comprising a machine having a reciprocatory needle bar carrying a needle, cooperating stitch forming means, a main drive shaft, connections from said shaft for reciprocating said needle bar and driving said cooperating stitch forming means, a thread supply means, means for controlling the delivery of thread from said supply means to said needle comprising a control shaft rotated in synchronism with said drive shaft, a plurality of cam elements rotated by said control shaft, thread guiding means adapted to retain different portions of said thread in the paths of movement of said cam elements. there being only a rockable eyelet carrying arm and stationary eyelet means in the path of movement of the thread from the region of said cam elements to the eye of said needle.
Claim 6
Dependent Claim
129 words
Sewing apparatus comprising a machine having a reciprocatory needle bar carrying a needle, cooperating stitch forming means, a main drive shaft, connections from said shaft for reciprocating said needle bar and driving said cooperating stitch forming means, a thread supply means, means for controlling the delivery of thread from said supply means to said needle comprising a control shaft rotated in synchronism with said drive shaft, a plurality of cam elements rotated by said control shaft, thread guiding means adapted to retain different portions of said thread in the paths of movement of said cam elements. there being only a rockable eyelet carrying arm and stationary eyelet means in the path of movement of the thread from the region of said cam elements to the eye of said needle.
Claim 7
Dependent Claim
140 words
Sewing apparatus comprising a machine having a reciprocatory needle bar carrying a needle, cooperating stitch forming means, a main drive shaft, connections from said shaft for reciprocating said needle bar and driving said cooperating stitch forming means, a thread supply means, means for controlling the delivery of thread from said supply means to said needle comprising a control shaft rotated in synchronism with said drive shaft, a plurality of cam elements rotated by said control shaft, thread guiding means adapted to retain different portions of said thread in the paths of movement of said cam elements, certain of said cam elements being arranged to cooperate with spaced apart portions of the thread, and other of said cam elements being arranged to cooperate with a single portion of said thread in spaced relation to the first mentioned portions of the thread.
Claim 8
Dependent Claim
140 words
Sewing apparatus comprising a machine having a reciprocatory needle bar carrying a needle, cooperating stitch forming means, a main drive shaft, connections from said shaft for reciprocating said needle bar and driving said cooperating stitch forming means, a thread supply means, means for controlling the delivery of thread from said supply means to said needle comprising a control shaft rotated in synchronism with said drive shaft, a plurality of cam elements rotated by said control shaft, thread guiding means adapted to retain different portions of said thread in the paths of movement of said cam elements, certain of said cam elements being arranged to cooperate with spaced apart portions of the thread, and other of said cam elements being arranged to cooperate with a single portion of said thread in spaced relation to the first mentioned portions of the thread.
Claim 9
Dependent Claim
38 words
In sewing apparatus as set forth in claim 5, said other of said cam elements involving relatively adjustable members adapted to vary the duration of activity of said cam elements upon a cycle of operation of the machine.
Claim 10
Dependent Claim
45 words
In sewing apparatus as set forth in claim 6, said certain of said cam elements having a duration of activity upon a cycle of operation of the machine that is longer than the combined duration of the activity of said other of said cam elements.
Claim 11
Dependent Claim
141 words
Sewing apparatus comprising a machine having a main drive shaft, a plurality of thread carrying elements arranged to cooperate to form stitches, connections from said shaft for operating said elements, means for controlling delivery of thread to one of said elements in a predetermined amount to insure its firm and uniform application to a work piece being stitched, said means comprising a device for applying a main tension to said thread in its path of movement from a supply source, means providing a plurality of stationary eyelets through which the thread is passed from said device, a plurality of cams arranged for rotation in the region of said eyelets, each of said cams having an outwardly extending portion adapted to engage the thread and apply a force thereto, whereby a stitch is applied to the work piece under a desired force.
Claim 12
Dependent Claim
141 words
Sewing apparatus comprising a machine having a main drive shaft, a plurality of thread carrying elements arranged to cooperate to form stitches, connections from said shaft for operating said elements, means for controlling delivery of thread to one of said elements in a predetermined amount to insure its firm and uniform application to a work piece being stitched, said means comprising a device for applying a main tension to said thread in its path of movement from a supply source, means providing a plurality of stationary eyelets through which the thread is passed from said device, a plurality of cams arranged for rotation in the region of said eyelets, each of said cams having an outwardly extending portion adapted to engage the thread and apply a force thereto, whereby a stitch is applied to the work piece under a desired force.
Claim 13
Dependent Claim
33 words
In sewing apparatus as set forth in claim 8, certain of said cams being adapted to pull thread from said supply source through said device for applying a main tension to said thread.
Claim 14
Dependent Claim
44 words
In sewing apparatus as set forth in claim 9, said device for applying a main tension to said thread comprising a pair of disks, a spring urging one of said disks toward the other, and adjustable means for varying the force of said spring.
Claim 15
Dependent Claim
30 words
In sewing apparatus as set forth in claim 8, said cams being carried by a shaft which is rotated at the same speed as themain drive shaft of the machine.
Claim 16
Dependent Claim
62 words
In sewing apparatus as set forth in claim 8, certain of said cams being adapted to pull thread from said supply source through said device for applying a main tension to said thread, and other of said cams being adapted to apply a further tension to said thread and to deliVer successive portions thereof to said one of said thread carrying elements.
Claim 17
Dependent Claim
69 words
In sewing apparatus as set forth in claim 8, said thread carrying elements comprising a reciprocatory needle and a rotary hook, said means for controlling delivery of thread serving to control the thread delivery to said needle and serving to supply the amount of thread needed to form a loop around the rotary hook and to then pull up said loop to the underside of the work being stitched.
Claim 18
Dependent Claim
71 words
In sewing apparatus as set forth in claim 13, said means for controlling delivery of thread to said needle including a rockable arm having an eyelet therein through which the thread is passed toward said needle, said arm serving to alternately provide and then take-up a certain length of thread that is sufficient to enable said hook to carry a loop of thread around a bobbin case within said rotary hook.
Claim 19
Dependent Claim
30 words
In sewing apparatus as set forth in claim 14, certain of said cams being adapted to pull thread from a supply source to make it available to form a stitch.
Claim 20
Dependent Claim
53 words
In sewing apparatus as set forth in claim 8, a presser foot which is spring urged downwardly against the work being stitched, manually operable means for lifting said presser foot, and connections from said manually operable means for shifting said normally stationary eyelets away from said cams when the presser foot is lifted.
Claim 21
Dependent Claim
29 words
In sewing apparatus as set forth in claim 16, said lifting of the presser foot being arranged to release the main tension applied to the thread by said device
Claim 22
Dependent Claim
273 words
Sewing apparatus comprising a sewing machine having thread carrying stitch forming elements and means for controlling the delivery of thread to at least one of said stitch forming elements from a supply, said thread controlling means comprising first and second means for applying variable tension to the thread, thread pull-off means, thread take-up means, said first thread tension applying means being adapted to apply a predetermined, constant, tension to the thread throughout a part of a stitch forming cycle, said second thread tension applying means being adapted to apply a considerably higher tension to the thread through one portion of the stitch forming cycle and completely releasing this higher tension during the remaining portion of the stitch forming cycle, said second tension applying means being located between said one of the stitch forming elements and said first tension applying means in the path of delivery of the thread, said thread pull-off means being adapted to pull off one portion of the amount of thread that is needed for forming a stitch, during the period when said second thread tension applying means applies said high tension, said thread pull-off means being located between said first and second tension applying means in the path of delivery of the thread, said thread take-up means being adapted to pull off from a supply the remaining portion of the thread needed for forming a stitch, during the period in the cycle when said higher tension is released, and said second tension applying means and said pull-off means being adapted to engage the thread in successive order with the second tension applying means first and the pull-off means later.
Claim 23
Dependent Claim
273 words
Sewing apparatus comprising a sewing machine having thread carrying stitch forming elements and means for controlling the delivery of thread to at least one of said stitch forming elements from a supply, said thread controlling means comprising first and second means for applying variable tension to the thread, thread pull-off means, thread take-up means, said first thread tension applying means being adapted to apply a predetermined, constant, tension to the thread throughout a part of a stitch forming cycle, said second thread tension applying means being adapted to apply a considerably higher tension to the thread through one portion of the stitch forming cycle and completely releasing this higher tension during the remaining portion of the stitch forming cycle, said second tension applying means being located between said one of the stitch forming elements and said first tension applying means in the path of delivery of the thread, said thread pull-off means being adapted to pull off one portion of the amount of thread that is needed for forming a stitch, during the period when said second thread tension applying means applies said high tension, said thread pull-off means being located between said first and second tension applying means in the path of delivery of the thread, said thread take-up means being adapted to pull off from a supply the remaining portion of the thread needed for forming a stitch, during the period in the cycle when said higher tension is released, and said second tension applying means and said pull-off means being adapted to engage the thread in successive order with the second tension applying means first and the pull-off means later.
Claim 24
Dependent Claim
25 words
In sewing apparatus as set forth in claim 18, said second tension applying means and said pull-off means being arranged to disengage the thread simultaneously.
Claim 25
Dependent Claim
44 words
In sewing apparatus as set forth in claim 18, said second tension applying means and said pull-off means each comprising cam means involving at least one cam, said cam means being mounted for rotation on a common shaft driven by the main drive shaft.
Claim 26
Dependent Claim
22 words
In sewing apparatus as set forth in claim 20, said cams being formed with outwardly extending portions arranged to engage the thread.
Claim 27
Dependent Claim
34 words
In sewing apparatus as set forth in claim 21, said outwardly extending portions of said cams being of a larger peripheral length on the tension applying cam means than on the pull-off cam means.
Claim 28
Independent Claim
110 words
A method of contRolling the delivery of thread to the needle of a sewing machine having a thread carrying needle and a cooperating thread carrying rotary loop taker, which comprises the steps of causing the needle to carry its thread through the work into cooperation with the rotary loop taker, pulling the needle thread up from the loop taker after it has been passed around the thread carried by the latter, applying a high tension force to the needle thread as it is being pulled from a loop taker, releasing said high tension when the needle thread has been pulled up to the work piece and the stitch is set.
Claim 29
Independent Claim
110 words
A method of contRolling the delivery of thread to the needle of a sewing machine having a thread carrying needle and a cooperating thread carrying rotary loop taker, which comprises the steps of causing the needle to carry its thread through the work into cooperation with the rotary loop taker, pulling the needle thread up from the loop taker after it has been passed around the thread carried by the latter, applying a high tension force to the needle thread as it is being pulled from a loop taker, releasing said high tension when the needle thread has been pulled up to the work piece and the stitch is set.
Claim 30
Dependent Claim
82 words
A method as set forth in claim 23 in which thread is drawn from the needle thread supply source during the application of a high tension thereto, said thread so drawn being stored outside of the area in which said thread is affected by the application of said high tension, and adding the thread so drawn from the needle thread supply when said high tension is released, and thereafter drawing further thread from said supply in preparation for the next stitch-forming cycle.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-08-15 | 1976-02-14 | 1976-08-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-15 | 1980-02-14 | 1980-08-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-15 | 1984-02-14 | 1984-08-15 | $7700.00 | Window Closed / Lapsed |