Tension selecting mechanism for sewing machines
First Claim
1. An improved tension selecting mechanism for a sewing machine having a frame including a work supporting bed and a hollow upwardly open bracket arm overhanging said bed, an arm top cover to enclose said open bracket arm having a horizontal slot formed therein, an endwise reciprocating thread-carrying needle, a needle thread tension device including a first thread engaging disc and a second thread engaging disc carried on a supporting stud for applying frictional resistance to the movement of a needle thread between said first and said second discs, an axially shiftable rod for moving said first thread engaging disc toward and away from said second thread engaging disc, a lever having a supporting fulcrum and a free end, means on said lever spaced from said fulcrum for engaging said axially shiftable rod, leaf spring supported relatively to said sewing machine frame and having a contact point formed at one end thereof to impart a spring bias to a location along said lever between said free end and said fulcrum to apply a tension to said axially shiftable rod, wherein the improvement comprises an operator influenced clamp means for adjusting the point of contact between said lever and said leaf spring, said clamp means including a stud projecting from said leaf spring through said slot in said arm top cover, said stud being substantially perpendicular to the axis of said lever, means associated with said stud for frictionally resisting movement thereof along said slot, and a selecting knob on said stud slidably carried exteriorly of said arm top cover for slidably varying the point of contact between said lever and said leaf spring.
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Accused Products
Abstract
A mechanism for selecting the tension setting of a needle thread tension device for sewing machines. A slot is formed in the face of the sewing machine arm top cover through which extends an operator influenced tension selecting knob. The tension device for influencing the needle thread tension is connected to the tension selecting knob by a leaf spring and lever fulcrummed to the arm top cover. Movement of the tension selecting knob along the slot in the arm top cover varies the force exerted on the needle thread by the tension discs contained within the tension device.
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Citations
1 Claim
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1. An improved tension selecting mechanism for a sewing machine having a frame including a work supporting bed and a hollow upwardly open bracket arm overhanging said bed, an arm top cover to enclose said open bracket arm having a horizontal slot formed therein, an endwise reciprocating thread-carrying needle, a needle thread tension device including a first thread engaging disc and a second thread engaging disc carried on a supporting stud for applying frictional resistance to the movement of a needle thread between said first and said second discs, an axially shiftable rod for moving said first thread engaging disc toward and away from said second thread engaging disc, a lever having a supporting fulcrum and a free end, means on said lever spaced from said fulcrum for engaging said axially shiftable rod, leaf spring supported relatively to said sewing machine frame and having a contact point formed at one end thereof to impart a spring bias to a location along said lever between said free end and said fulcrum to apply a tension to said axially shiftable rod, wherein the improvement comprises an operator influenced clamp means for adjusting the point of contact between said lever and said leaf spring, said clamp means including a stud projecting from said leaf spring through said slot in said arm top cover, said stud being substantially perpendicular to the axis of said lever, means associated with said stud for frictionally resisting movement thereof along said slot, and a selecting knob on said stud slidably carried exteriorly of said arm top cover for slidably varying the point of contact between said lever and said leaf spring.
Specification
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- Resources
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Current AssigneeSinger PLC (Hayleys Plc)
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Original AssigneeSinger Company (SVP Holdings Ltd.)
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InventorsRoss, Roger J.
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Primary Examiner(s)Reynolds, Wm. Carter
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Application NumberUS05/892,066Time in Patent Office634 DaysField of Search112/254, 112/255, 112/59, 112/97, 242/150 RUS Class Current112/254CPC Class CodesD05B 47/00 Needle-thread tensioning de...
