US2219211A - Looper and feeding mechanism for sewing machines - Google Patents

Description

C. C. SMITH ET AL Oct. 22. 1940.

LOOPER AND FEEDING MECHANISM FOR SEWING MACHINES 3 Sheets-Sheet l INVENTORS:

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(7a u 4 W ATTORNEY Oct. 22, 1940. C Q sMlTH r AL 2,219,211

LOOPER AND FEEDING MECHANISM FOR SEWING MACHINES Filed Feb. 5, 1938 3 Sheets-Sheet 3 FIG-P: 41f

FIG A.

FIG II.

INVENTORS: Claicence (I. ,Siniih 23:.

.4 TTORN YS.

PATENT OFFICE v V 2,219,211 LOOPER nn FEEDING MECHANISM ron .SEWIN GMACHINES Clarence C. Smith, Chicago, and George Saucr,

Bcrwyn,

Ill., assignors to Union Special Machine Company, Chicago, 111., a corporation of Illinois Application February 5, 1938, semi No. 188,837

10 Claims.

mechanism for sewing machines; and it has reference more particularly to looping and feeding mechanism for sewing machines ofthe type wherein the looping and feeding mechanism is disposed below the work supporting surface and arranged to be operated from a horizontal shaft at the level'above the work support.

The chief aim of our invention is to secure a more perfect balance between the looping and the feeding elements, and at the same time to reduce in number the parts required for their actuation, with a view toward minimizing vibration and thereby enabling operation of the sewing machines at higher speeds than possible heretofore, and attaining a correspondingly increased output or production from them.

This desideratum we realize in practice, as hereinafter more fully disclosed by arranging the looper shaft and the feed bar in parallelism and providing a double arm rocker which is medially-fulcrumed to oscillate about a transverse axis intermediate the looper shaft and the feed bar with its opposite extremities connected to the shaft and the bar in such manner that the latter are longitudinally 'reciprocated contrari-- wise to induce needle-approaching and needleavoiding movements of the loopers and feeding movements of the feed dog.

In connection with the looping and feeding mechanism wherein the looper shaft and the feed bar are longitudinally reciprocated contrariwise as above set forth, it is a further aim of our invention to enable impartation of oscillatory movements to the looper shaft and thereby induce loop taking and retractive movements of the looper; and rocking movements to the bar and in turn induce up and down or lift movements of the feed dog without interfering with the feed bar support against lateral vibration and bending through provision therefor of a pivoted sleeve in which it is effectively held incident to moving endwise.

Another object of our invention is to secure the foregoing advantages in looping and feeding mechanism whereof the component parts lend themselves to ready manufacture and assembling at small cost.

Other objects and attendant advantages will (Cruz-215) This invention relates to looping and feeding appear from the following detailed description of the-attached drawings, wherein Fig. I is a view partly in side elevation and partly in'longitudinal section of a sewing machine embodying our improved looping and feeding mechanism.

' Fig.1]; is a plan view of the work support of the machine with its cover members removed.

Fig. III is a longitudinal sectional view of the work support.

Fig. IV is a fragmentary view showing the front end of a work support in'plan.

Fig. V is a horizontal detail section of the rear end of the work support taken as indicated by the arrows VV in Fig. III.

Figs. VI, VII, VlII, IX and X are. detail cross sectional views taken as indicated respectively by the arrows VIVI, VIIVII, VIII VlII. IX-IX, and XX in'Fig. III.

, The sewing machine chosen for convenience of exemplifying our invention is of the feed-oftthe-arm type, generally like the one illustrated and described in U. S. Patent #1,74l,095, granted on Dec. 24, 1929, to NormanV. Christensen and Harold J. LeVesconte, in that it has a frame with a horizontal tubular elevated portion l which is integrally formed with a'bracket-like base 2, and a pendant hollow vertical portion 4 whereto is detachabiy connected a hollow horizontal work-supporting arm 3, the free end of which underreaches a laterally projecting head 5 at the corresponding end of-said elevated tubular portion. Guided for vertical reciprocation in the head 5 is a bar 6 whereto a pair'of needles l are secured at the lower end. Also confined to axial movement in the head 5 is a vertical presser bar 8 which carries' a presser foot 9 at its lower end. Through suitable connections (not illustrated) up and down movements are induced in the needle bar 6 from a shaft III which extends longitudinally through the tubular frame.

portion I. As shown, the shaft l0 protrudes machine where it is provided ith a combined hand and belt wheel I! so that the machine may beoperated either manually or by power.

a Within the hollow of the vertical frame portion 4 at a level intermediate the work support 3 and the needle actuating shaft III is a parallel countershaft II which is driven, through a pair of intermeshing spur gears l8, l9, from said needle shaft, and which is journaled at opposite ends in bearings 20, 2!, respectively set into the opposite side walls IG and 22 of said vertical frame portion. The countershaft I1 is formed with a through a bearing H at the front end of the: I

plurality of rotary actuators in the form of cranks 23, 24 and 25 which through drop links 26, 21, 23' serve to Y actuate our improved complemental stitch-forming and feeding mechanism in a manner presently explained. The countershaft and gear construction just described constitutes the subject matter of a separate patent application Serial No.-188,836 filed by us concurrently herewith.

The complemental stitch-forming and feeding means with which the present invention is more especially concerned is housed within the hollow of the work supporting arm 3, and as shown in Figs. II-X, includes a longitudinally extending shaft 36 which is journaled in spaced bearings 3|, 32 and'33 at the bottom of the work support with capacity for both endwise and oscillatory movement. Secured to the outer end of the shaft 36 is aholder 34 for a pair of loopers 35 arranged to cooperate in a well known manner with the needles 1 in stitch formation. The shaft 36 is reciprocated endwise to induceneedie-avoiding movements in the loopers 35 through a link 31. At one end, the link 31 is pivoted to a laterally-projecting stud 38 of a cross head 36 confined between a pair of fixed collars 46 on the looper shaft 36, and at its other end, said link carries a stud 4| capable of adjustment'along a longitudinal slot in the pendant extremity 42a of a double arm rocker 42 affixed to a transverse shaft 43 at a level intermediate said looper shaft and an overlying feed bar 46. As shown in Figs.

V and x, the transverse shaft 43 has its opposite ends journaled in bearings 41, 48 whereof the former is set into one of. the side walls of the work arm 3, and the latter into an upstanding lug 43 within said work arm. From Figs. III and IX, it will be observed that the cross head 39 has a downward-projection 56 which engages .within the interval between longitudinally-ar ranged guide blocks 5| .at the bottom of the work arm 3. To the inner end of the looper shaft 36 beyond the bearing 33 is secured a crank arm 52 with a laterally-projecting stud 53 which present applicants) on June 22, 1937, a feed dog about a transversely extending pin 58 whereof.

56. In the present construction, the feed bar 46 is supported for endwise sliding movement in a pivoted slideway having the form of a supporting sleeve 51 which is medially pivoted to rock the ends are engaged in inwardly-projecting bosses 53 and 66 at opposite sides of the work support 3. sleeve 51 to induce feeding movements of the feed dog 56, through a link 6| which, atone end is pivotally connected to a head 62 at the rear end of said "bar, said head having its shank 62a extending into said bar and secured by a clamp collar 63. At its other end, the link 6| carries a clamp screw stud 64 arranged for adjustment along the longitudinal slot in the upward extremity 42b of the double arm rocker 42. Integrally formed with the rocker 42 is a rear- The bar 46 is reciprocated within the wardly-extending horizontal arm 420, which carries a ball stud whereby it .is connected to the lower end of the vertical link 21-- which extends down from the crank 24 on-the-countershaft l1. Up or down or liftmovements' are communicated to the feed dog 56 as a resultfof rocking of the sleeve 51 about the pivot; 56,, such motion being imparted from the crank23 on the countershaft l1 through the link 26, which, at its lower end is coupled with a ball stud 66. on an arm 51a extending rearwardly from said sleeve. Rotation of the feed bar 46 is prevented as a consequence of engagement of the squared shank 54 of the feed dog-supporting head 55 in a correspondingly-configured recess 66 in the outer end wall 61 of the work arm 3, see Figs. II and VII. The teeth of the feed dog 56 operate through the longitudinal slots of a throat plate 69 secured cantilever-fashion to the outer end of the work arm 3 by screws 10. The parts-within the work arm 3 are accessible from above upon removal of atop cover plate shown at 1| in Figs. III. VIII and IX, and the loopers -35 and'the feed dog 56 are exposed for the purposes of'inspection or adjustment upon withdrawal of a removable end cap indicated at 12 in Figs. I, III, IV, v: and VII.

The operation of the mechanism is as follows:

By the action of the crank 24 on the countershaft l1 upon the link 21, the mcdially-fulcrumed double 'arm rocker 42 is continually oscillated, and through it and the associated horizontal links 31 and 6|, the looper shaft 3|! and the feed bar 46 are reciprocated endwise, that is to say, the looper shaft is shifted in one direction while the feed bar is shifted in the other and vice versa. Since, as will be apparent fromFig. III, the looper shaft 36 and its appendages are so proportioned as to have a total weight equal substantially to that of the feed bar 46 and its appendages, the endwise movements of one will be balanced by the contrariwise endwise movements of the other. Moreover, since the retractive swing of the loopers 35 must of necessity take place concurrently with the rising movement of the feed dog 56 .and vice-versa. a balanced action is also had between the oscillations of the looper shaft 36 and of the pivoted guideway 51 in which the feed bar 46 is effectively held and controlled againstlateralfiexure and vibration in its endwise movements. It accordingly follows that our improved looping and feeding mechanism is smooth and noiseless in its action and therefore favors running of the sewing machine at high speeds. In order to adapt the machine for operation upon different kinds of material, the movements of the loopers 35 and the feed dog 56 may be increased or decreased simply by shifting the studs 4| and 64 of the links 31 and 6|- respectively along the slotted extremit es of the double arm rocker 42, said studs being accessible for this purpose upon removal of the screw plugs ,shown at 13 and 14 in Figs. I and X from access openings in one side of the work arm 3.

Attention is also directed to the fact that the component parts of the mechanism are of simple design and therefore easy to manufacture and assemble at low cost.

Having thus described our invention, we claim: 1. Looping and feeding mechanism for chain stitch sewing machines comprising a looper shaft, a parallel feed bar, a double arm rocker medially fulcrumed to oscillate about a transverse axis intermediate the shaft and the bar, said rocker having slots longitudinally of its opposite extremiti'es, a link pivoted at one end to the shaft and carrying a stud at its other end adjustable along the slot of one of the extremities of the rocker, another link similarly connecting the feed 5 bar with the other extremity of the rocker, and means for actuating the rocker,

2. Looping and feeding mechanism for chain stitch sewing machines comprising a looper shaft, a parallel feed bar, a support wherein the bar is confined for axial reciprocation, said support being mounted on a transverse pivot, a double arm rocker medially fulcrumed on a transverse axis, a link connecting the shaft to one extremity of the rocker, another link connecting the feed bar to the other extremity of the rocker, and means for actuating the rocker and for oscillating the feed bar support on its pivot.

3. Looping and feeding mechanism for a chain stitch sewing machine having a horizontal rotary shaft at a level above a horizontal work supporting surface, said mechanism comprising a horizontal looper shaft, a parallel feed bar, a double arm rocker medially fulcrumed to oscillate about a transverse axis intermediate the looper shaft 35 and the feed bar, means connecting the opposite extremities of the rocker respectively with the looper shaft and the feed bar, said looper shaft, feed bar, rocker and connecting means being all beneath the work supporting surface, and an 30 actuating connection extending down from the rotary shaft aforesaid to the rocker.

4. Looping and feeding mechanism for a chain stitch sewing machine having a horizontal rotary shaft at a level above a horizontal work supporting surface, said mechanism comprising a horizontal looper shaft, a horizontal feed bar overlying the looper shaft and carrying a feed dog, a vertically-arranged double arm rocker medially fulcrumed to oscillate about a transverse axis 1 intermediate the looper shaft and the feed bar,

means whereby the pendant and upwardly extending extremities of the rocker are respectively coupled to the looper shaft and the feed bar, said looper shaft, feed bar, rocker and connecting 45 means being all below the work supporting surface, and an actuating connection extending down from the rotary shaft to the rocker.

5. Looping and feeding mechanism for a chain stitch sewing machine having a horizontal rotary IQ shaft at a level above a horizontal work supporting surface, said mechanism comprising a horizontal looper shaft, a horizontal feed bar overlying the looper shaft and carrying a feed dog, a vertically-arranged double arm rocker medially g5 fulcrumed to oscillate about a transverse axis intermediate the looper shaft and the feed bar, means whereby the pendant and upwardly extending extremities of the rocker are respectively coupled to the looper shaft and the feed bar, said Q looper shaft, feed bar, rocker and connecting means being all below the work supporting surface, and a link extending down from an actuator crank on the rotary shaft aforesaid to the rocker. 6. Looping and feeding mechanism for a chain stitch sewing machine having a horizontal work supporting surface and a horizontal rotary shaft at a higher level, said mechanism comprising a horizontal looper shaft supported with capacity for endwise reciprocation and oscillation, a hori- 1. zontal feed bar. a support pivoted on a transverse axis and guiding the feed bar for endwise movement, is double arm rocker medially mlcrumed to oscillate about a transverse axis intermediate the looper shaft and the feed bar, means whereby the opposite extremities of the rocker are respectively connected to the looper shaft and the feed bar, said looper shaft, bar, rocker, pivoted sup- 5 port and connecting means being all below the work supporting surface, and separate connections extending down from the rotary shaft to oscillate the looper shaft, to actuate the rocker, and to oscillate the pivoted support for the feed 10 bar.

'7. Looping and feeding mechanism for a chain stitch sewing machine having a horizontal work supporting surface and a horizontal rotary shaft at a higher level, said mechanism comprising a 15 horizontal looper shaft supported with capacity for endwise reciprocation and oscillation, a horizontal feed bar, a support pivoted on a transverse axis and guiding the feed bar for, endwise movement, a double arm rocker medially fulcrumeld to 20 oscillate about a transverse axis intermediate ,the

looper shaft and the feed bar, means whereby the opposite extremities of the rocker are respectively connected to the looper shaft and the feed bar, said looper shaft, bar, rocker, pivoted support and connecting means-being all below the work supporting surface, and links extending down from actuating cranks on the rotary shaft and connected respectively to a crank arm on the looper shaft, to the'rocker, and to the pivoted support for the feed bar. a

8. The combination with looper and feeding mechanism for chain stitch sewing machines comprising an oscillating and endwise reciprocating looper shaft, a rocking and endwise reciproeating feed bar carrying a feed dog at one end thereof, and means for inducing simultaneous endwise movements of said'looper shaft and feed bar in opposite directions; of a movable supporting guide in which the bar is guided in its endwise 40 reciprocation, and a fixedguide which engages the feed bar beyond the movable guide and prevents said bar from rotating about its own axis.

9. The combination with looper and feeding mechanism for chain stitch sewing machines comprising an oscillating and endwise reciprocating looper shaft, a rocking and endwise reciprocating feed bar with a feed dog at one end thereof,and means for inducing simultaneous endwise movements of said looper shaft and feed bar; of a movable supporting guide in which the feed bar is guided in its endwise reciprocation, and a fixed guide which engages the feed bar adjacent the feed dog, and prevents said bar from rotating about its own axis.

10. The combination with looper and feeding mechanism for a chain stitch sewing machine comprising an oscillating and endwise reciprocating looper shaft, a rocking and endwise reciprow eating feed bar and means for inducing sin ul-go taneous endwise movements of said looper'shaft and feed bar in opposite directions, of a movable guide in which the feed bar is guided in its end-- wise reciprocation, and a fixed guide whichv engages the feed bar beyond the movable guide and as prevents said bar from. rotating about its own axiasaid shaft with its appendages and said bar with its appendages being so proportioned and arranged as to substantially balance eachother in thei movements. 1

,, CLARENCE (I. SMITH. GEORGE BAUER.

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