US2441937A - Sewing machine loop-taker mechanism - Google Patents

Description

May 18, 19.48. I 1 2,441,937

SEWINGMACHINE LOOP-TAKER MECHANISM siied March 16, 1945 Patented May 18, i948 UNITED STATES PATENT OFFICE SEWING MACHINE LOOP-TAKER MECHANISM Charles A. Kessler, Plainfield, N. J., assignor to The Singer Manufacturing Company, Elizabeth, N. J a corporation of New Jersey Application March 16, 1945, Serial No. 583,092 6 Claims. (01. 112256) This invention relates to devices for lubricating the thread-carrier raceways of sewing machine loop-takers and, more particularly, the thread-carrier raceways' of loop-takers of the horizontal-axis rotaryhook type.

The present invention has for its primary object to provide means for obtaining proper lubrication of the thread-carrier raceway of a sewing machine loop-taker at any speed of operation of the machine.

More specifically, it is an object of this invention to provide improved means insuring delivery to a rotary hook raceway of a quantity of lubricant which may be regulated to meet requirements at different speeds of operation of the machine.

With these and other objects in View, as will hereinafter appear, the invention consists in the devices, combinations and arrangements of parts hereinafter described in connection with the accompanying drawings, which illustrate a preferred embodiment of the invention and in which:

Fig. 1 represents a Vertical longitudinal section of a portion of the bed-plate of a sewing machine containing the present improvement. Fig. 2 rep resents a horizontal longitudinal section of the loop-taker shaft mechanism; the loop-taker being shown as partly broken away. Fig. 3 represents a vertical section of the loop-taker shaft and its bushing; the section being taken substantially on the line 33 of Fig. 1. Fig. 4 represents a section similar to Fig. 3, but taken substantially on the line 44 of Fig. 1. Fig. 5 is an end elevation of the inner end of the loop-taker shaft bushing and pinion.

The present rotary hook mechanism comprises a modification of that disclosed in the U. S. patent of S. Zonis, No. 2,267,581, December 23, 1941, to which reference may be had for a more complete disclosure of the sewing machine.

The sewing machine in part illustrated in the drawings has a work-supporting bed-plate l6 provided with a throat-plate I having a needleaperture l2. The bed-plate ID has depending walls formed to provide a gear-casing and oilreservoir chamber I3 having a bottom closureplate l4 suitably secured to said walls.

Secured by a screw l5 in a wall I 6 of the gearcasing, is a bushing H in which is journaled a horizontally disposed rotary actuating shaft la.

The shaft l8 may be rotated by any suitabledriving connections therewith; for example, as shown in the prior Patent No. 2,267,581 hereinbefore mentioned. Secured to the end of the-shaft 2 l8 within the oil-reservoir chamber I3 is the hu of an internal driving gear l9.

In mesh with the teeth of the internal gear I!) is a pinion having its horizontal axis of rotation preferably lying in a vertical plane containing the axis of rotation of the driving shaft H3. The ratio of the internal gear l9 and pinion 20 is such that said pinion rotates twice for each rotation of the gear l9. The pinion 20, which is also disposed in the oil-reservoir chamber I3, is carried by one end of a horizontally disposed loop-taker shaft 2| and is preferably integral with said shaft. Secured by screws, as 22, upon the opposite end of the shaft 2| is the hub 23 of a rotary-hook form of loop-taker 24. The looptaker 24 has the usual cup-shaped body which is provided in its cylindrical side wall with a raceway 25 for the peripheral bearing-rib 26 of a thread-carrier 21 journaled in the loop-taker; said thread-carrier 21 being restrained, in any usual or suitable manner, against rotation with the loop-taker. The loop-taker shaft aperture in the hub 23 of the loop-taker is closed by a disk 28 set into the bottom wall 29 of the loop-taker; the loop-taker being, as usual, mounted upon the shaft 2| so that the end of said shaft is spaced from the disk, whereby an oil-collecting recess 33 is provided in the loop-taker. Connecting the oil-collecting recess 30 and the raceway 25 is an angular lubricant-duct 3| provided in the body of the loop-taker.

The loop-taker shaft 2| is rotatably journaled in two horizontally spaced bearing- sleeves 32 and 33, which sleeves are suitably secured in the iongitudinal opening 34 of a bushing 35. The sleeve 32 forms a bearing for the shaft 2| adjacent the loop-taker 24 and the sleeve 33 forms a bearing for said shaft adjacent the pinion 20; the spacing of said sleeves providing a lubricant-collecting cavity in the bushing-opening 34 between the sleeves. The bushing 35 is secured in a horizontal opening, provided in the wall 36 of the gearcasing, by a screw 3'! which enters a groove 33 formed in the outer face of the bushing to extend lengthwise thereof. The described construction provides for assembly of the loop-taker shaft 2| and its bearing- sleeves 32, 33 in the bushing 35 g as a unit construction, as well as for axial adjustment of the loop-taker 24 by endwise adjustment of the bushing 35 in the frame-wall 36.

One end portion of the bushing 35, extending into the oil-reservoir I3, is partly cut away to form a segmental extension 35' which partly surrounds the pinion 20. and affords the necessary clearance for engagement of the driving-gear I9 its upper face IO ation of the machine, by the oil-throwing action.

of the driving-gear I9 which dips'into a supply of oil in the chamber l3. Leading downwardly from the bottom wall of the oil-collecting cavity 42 is an inlet oil-duct 43 provided in the bushing 35 and disposed in vertical-alimement with an inlet oil-duct i l provided radially in the bearing-sleeve 33.

The loop-taker shaft 2! is exteriorlyprovided, in the portion of the shaft within the sleeve 33, with a spiral groove -45 which terminates at one end in a radial aperture-400i the shaftZl. The lead of thespiral -groove 45is such'as to feed oil 'from the sleeve-duct M to the inlet shaftaperture 46 upon operation of the machine. I Furthermore, the pitch of the spiral groove 45 is preferably sufficiently steep to insure that oil is forced into the shaft-aperture le under a pres sure which'is-greater than'the centrifugal force action which-would oppose entrance of oil into the shaft-aperture' iii. Theshaft zl hasa'longitudinal bore 41 extending from'the loop-taker end of the-shaft to a point adjacent the pinion 20,- .and' the-shaft-aperturest communicates with the shaft-bore'fl intermediate the ends of said bore. It will therefore-be-understood that during'the operation of th machine, oil is not only fed or pumped under pressure into the shaft bore 41, but oil pressure is also built up in said shaft bore.

Threaded into the loop-taker end of the shaft 2l' isa hollow cartridge 58 having 'its-head'en'd provided-witha screw-driver slot. The cartridge 58 is internally threaded to retain therein one end 'of-an oil-filtering wick 49 which extends a substantial distance into the shaft-bore 41. At

the headi-end-of the cartridge, the internally threaded portion thereof terminates in an axial cartridge-aperture :59 of'reduced size and which is open to the oil-collecting recess 35 of -.the loop-taker. V

Adjacent/the inner end of the-shaft-bore '41 and at the side'ofthe sleeve oil-duct dd opposite the radial shaft-aperturefit, the shaft H is radially provided with an outlet shaft-aperture 5i-whichconnects theshaft-bole Ill with an annular qgroove 5'2 provided internally of the bearing-sleeve'33. As illustrated in'Figs. 2 and 3 ofthedrawings, the bearing-sleeve3 is radially provided with a dischargeor outlet duct 53 extending 'horizonta -ly from the sleeve-groove 5'2 and preferably disposed substantially at the level of the shaft-bore' ll. The bushing 35 is also radiallyprovided with a discharge or outlet duct '54 communicatingwith'the 'duct 53 of the bearing sleeve; said duct 54 being formed in theirrner end portion of the bushing'35 which extends into the oil-reservoir chamber 33. The'shaft-aperture 5|, sleeve-groove 52 and aimed :outlet ducts 53 and l'i l'together comprise'a :pressurerelief port for the oil pumped into the (shaft-bore 41- by the spiraltgroove 45 zoftheshaft.

In order to. providemeansi for regulating the effectiveness "of the described pressure-relief; port, the bushing fl: lS"IOIIQiCUdiTlQZIlY'IIflOWfiSd with a 4 stepped bore having a reduced portion 55 thereof intersecting the bushing-duct 5 3. Threaded into the bushing-bore 55, for endwise adjustment, is a shouldered valve-rod 55 disposed substantially parallel to the loop-taker shaft 2! and having its inner end conically shaped to provide a needle-vaive 55. By endwise adjustment of the-'valveerod 55, theposition of the needle valve 55' may be regulated to vary the size of the pressure-relief duct, or completely to close said duct.

The shaft-bearing face of the sleeve 33 is,'of course, directly lubricated by the oil supplied through the sleeve oil-duct 44 and also, in part, by the oil discharge through the radial shaftaperture 51. :In orderto insure adequate lubrication-of the shaft-bearing face of the sleeve 32,

said sleeve is provided in its inner face with a groove '55! extending lengthwise of the sleeve. Lying in the groove 5'i 'is one end portion of a wick -58,;of which. the other end extends into contact with the i-nneri-bottom face of the bushing 35 in the bushings-opening 34 between the sleeves 32 and Some excess oil -fed by the spiral groove d5 will be discharged into the bushing-openingS between the bearing- sleeve 32, 33. In "this manner, oil'is supplied to the wick 58 and is'fed thereby to the bearing-face of the sleeve 32. The portionof the sha-ft 2| within the sleeve 32 is exteriorly formed with a spiral;groove 59 having 'a-leadsuch as to feed excess oil back into the bushing-opening -34 betweenthe I bearing-sleeves.

The quantity of oil which may collect in the bushing-opening l, 34 is limited by the provision in the bushing 35 of a drain-aperture 89 having its inlet end disposed. slightly above the level of the lowest portionsof the opening 34. The aperture til is connectedewith the external bushing-groove 3B,-of I whichone 'endextends' into the oil-reservoir chamber t3.

From-the foregoing-:descr-iption,"it will be understood that, during the'operation of themachi-ne, oil is continuously pumped under pressure into the loop-taker s-ha-f-tbore 4'. and that the oil is pressure fed through-the oil-filtering wick 49 and through the restricted cartridge-aperture 555 into the-loop-taker recess '35, from-which recess the-oil is delivered through-"thelubricant-duct 3! to the raceway -25 of the loop-taker. By endwiseadjustment of the valve-rod 56; themessure of--the oil withinthelooptaker shaft bore 4'! may be regulated to a nicety to meet the requirements of different operating speeds and difierent kinds of work. To provide-for access to the head end For the Valve-red 56, it is sim ply necessary to withdraw the thread-case 6i fromlits carrier 2'? which isjour-naled in the looptaker; the usual construction of the bottom walls of the thread-case-lcarrier -21 and of the-looptaker 25 being suchas to-permi-t of use of a screwdriver for adjustingthe valve-rod. The present construction, thereforaprovides for adjustment of the oil-pressure in the -shaft-bore without removal of the loop-taker from the shaft 2:,

Having thus .set forth the nature of the invention, what I claim herein is:

1. In a sewing machine, 'a rotaryloop-taker having a thread-carrier raceway, a loop-taker carrying shaft provided with a' longitudinalbore and with radial inlet and outlet apertures in the wall thereof and open to said bore,'m'eans rendered efiective upon rotation of said shaft for supplying" lubricant under pressure through said, inlet aperture'into the bore of said shaft, -lubri-- cant-conducting means connecting the bore of said shaft and said raceway, a pressure-relief duct connected with said outlet aperture of the shaft, and manually adjustable means for varying the size of said pressure-relief duct.

2. In a sewing machine, a rotary shaft having a longitudinal bore and having inlet and outlet apertures in the wall thereof and open to said bore, a loop-taker carried by said shaft and having a thread-carrier raceway, lubricant-conducting means connecting the bore of said shaft and said raceway, a lubricant-supply reservoir, pump means effective upon rotation of said shaft for supplying lubricant under pressure through said inlet aperture into said bore of the shaft, and adjustable means connected with said reservoir for bleeding lubricant from said bore of the shaft through said outlet aperture.

3. In a sewing machine, a rotary loop-taker having a thread-carrier raceway, a rotary looptaker carrying shaft provided with a longitudinal bore and with inlet and outlet apertures in the wall thereof and connected with said bore in spaced relation to said loop-taker, lubricantconducting connections with said bore of the shaft for directing lubricant to said raceway, a sleeve embracing the portion of said shaft containing said inlet aperture, one of the proximate faces of said shaft and said sleeve being provided with a spiral groove leading to said inlet-aperture of the shaft, means effective upon rotation of said shaft for supplying lubricant to said spiral groove, and adjustable means for regulating the flow of lubricant through said outlet aperture.

4. A loop-taker assembly unit for sewing machines, comprising, a bushing rovided with lubricant-inlet and lubricant-outlet apertures, a sleeve secured in said bushing and provided with lubricant-inlet and lubricant-outlet apertures communicating with the corresponding apertures of said bushing, a shaft rotatably journaled in said sleeve and provided with a longitudinal bore and with radial lubricant-inlet and lubricantoutlet apertures communicating with the corresponding apertures of said sleeve, 2. loop-taker carried by one end of said shaft and provided with a thread-carrier raceway having lubricanteating with the corresponding apertures of said sleeve, said lubricant outlet being located nearer to the closed end of said bore than is said lubricant-inlet, a loop-taker carried by the end of said shaft remote from the closed end of said bore and said loop-taker being provided with a threadcarrier raceway having lubricant-conducting connections with said bore of the shaft, one of the proximate faces of said shaft and sleeve being provided with a spiral groove having a direction of lead to pump lubricant from the lubricant-inlet aperture of said sleeve and into the lubricant-aperture of said shaft, and a valve-rod adjustably carried by said bushing in parallel relation with said shaft, said valve-rod being accessible for adjustment at the loop-taker end of said bushing and being adapted to extend into said outlet aperture of the bushing.

conducting connections with said bore of the V shaft, one of the proximate faces of said shaft and sleeve being provided with a spiral groove rendered effective upon rotation of said shaft to pump lubricant from the lubricant-inlet aperture of said sleeve and into the lubricant-aperture of said shaft, and valve means for regulating the flow of lubricant through the communicating lubricant-outlet apertures of said shaft, sleeve and bushing.

5. A loop-taker assembly unit for sewing machines, comprising, a bushing provided with lubricant-inlet and lubricant-outlet apertures, a sleeve secured in said bushing and provided with lubricant-inlet and lubricant-outlet apertures communicating with the corresponding apertures of said bushing, a shaft rotatably journaled in said sleeve and provided with a longitudinal bore closed at one end and having radial lubricantinlet and lubricant-outlet apertures communi- 6. In a sewing machine having a bed-plate provided with a lubricant-reservoir, in combination, a horizontally disposed bushing secured in said bed-plate and provided within said resenvoir with lubricant-inlet and lubricant-outlet ducts, a pair of bearing-sleeves disposed in and spaced from each other lengthwise of said bushing, thereby providing a lubricant-collecting cavity in said bushing between said sleeves, a lubricant-drainage duct leading from said cavity and terminating in said reservoir, a shaft rotat-. ably journaled in said bearing-sleeves and provided with a longitudinal bore and with radial lubricant-inlet and lubricant-outlet apertures, a first. one of said sleeves having radial inlet and outlet apertures connecting with the corresponding ducts of said bushing, and said outlet aperture of the sleeve connecting with the outlet aperture of said shaft, a loop-taker carried by said shaft and having a thread-carrier raceway, lubricant-conducting connections between the bore of said shaft and said raceway, said shaft being provided within said first one of said sleeves with a spiral groove leading from said inlet aperture of the sleeve to said inlet aperture of the shaft,

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,230,461 Brush June 19, 1917 2,098,904 Waterman Nov. 9, 1937 2,267,581 Zonis Dec. 23, 1941 2,283,869 Graesser May 19, 1942 2,300,388 Parry Oct, 27, 1942 2 329,487 Sauer Sept. 14, 1943

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