US2367046A - Lubricating device for sewing machine loop-takers - Google Patents

Description

Jan. 9, 1945. F. PARRY 2,367,046

LUBRICATING DEVICE FOR SEWING MACHINE LOOP-TAKERS Filed Sept. 5, 1942 V V I 221.

[Fan/i Parry Patented Jan. 9, 1945 UNITED STATES LUBRICATING DEVICE FOR SEG MACHINE LOOP-TAKERS Application September 3, 1942, Serial No. 457,148

16 Claims.

This invention relates to loop-taker mechanisms for sewing machines and, more particularly, to loop-takers of the vertical-axis rotary hook type.

The invention has for its primary object to provide means insuring automatic delivery of lubricant in controlled quantity, during the operation of the sewing machine, to the thread-carrier raceway of a vertical-axis rotary loop-taker from a substantial supply of lubricant.

It is a further aim of the invention to effect the delivery of lubricant to the loop-taker raceway solely while the machine is in operation and from a supply of lubricant disposed above the level of the loop-taker.

With these and other objects in view, as will hereinafter appear, the invention comprises the devices, combinations and arrangements of parts described in connection with the accompanying drawing, which illustrates a preferred embodiment of the invention and in which:

Fig. l is a front side elevation, partly in vertical section, of a two-needle sewing machine containing the improved lubricating device. Fig. 2 represents an enlarged vertical section of one of the rotary loop-takers of the machine. Fig. 3 represents an enlarged vertical section of the externally threaded stem employed in conjunction with the loop-taker shaft for insuring the delivery of lubricant to the loop-taker raceway during the operation of the machine.

The sewing machine shown in the accompanying drawing has a frame including a horizontally disposed work-supporting bed-plate I, from one end of which rises the standard 2 of a bracketarm terminating at its free end in a head 3 overhanging the work-support. Journaled for vertical reciprocation in the bracket-arm head 3 is a needle-bar 4 carrying at its lower end atransverse holder 5 for a pair of vertically disposed needles 6 which are laterally aced from each other lengthwise of the bed-plate I.

The work is advanced crosswise of the bedplate by a feed-dog I which operates through the work-support and which may be actuated in any usual or suitable manner. Yieldingly opposed to the work-engaging movements of the feed-dog I is a conventional presser-foot 8.

Complemental to the respective needles 8 in the formation of lock-stitches are two loop-takers in the form of rotary hooks 9 disposed below the work-support I. As the rotary hooks 9 are of substantially the same construction, the right hand hook illustrated in Fig. 2 will be referred to in the description.

The rotary hook 9 has an upwardly open cupshaped body including a horizontally disposed bottom wall It! and a cylindrical side wall It. The side wall H of the rotary hook is cut away to provide a needle-thread loop seizing and spreading beak 12; said side wall I l of the rotary hook being internally provided with a raceway i3. Journaled in the raceway I3 of the rotary hook is a thread-carrier it which is restrained in a conventional manner against rotation with the rotary hook.

The rotary hook 9 is carried by the upper end of a vertically disposed rotary shaft i5 which, in the present case, is integral with the bottom wall 10 of the hook. While it is preferred to have the rotary hook 9 integral with its shaft [5, it will be apparent that the rotary hook may be detachably or otherwise secured to the hook-shaft in any usual or preferred manner. The axis of rotation of the rotary hook shaft I5 is substantially parallel to the needle 8 and is therefore substantially normal to the horizontal plane of the work-support I.

The hook-shaft I5 is rotatably journaled in vertically spaced lugs l6 and ll of a hook-saddle or bracket 18 disposed below the work-support i and'supported by conventional means. The upper bracket-lug It has a vertical opening 19 to receive a ball-bearing 20 in which is Journaled the upper portion of the hook-shaft [5. The lower lug I! of the bracket l8 also has a vertical opening 2| to receive a bearing-bushing 22 in which the lower portion of the hook-shaft I5 is journaled; said bearing-bushing 22 being suitably secured in the bracket-lug [1.

Between the bracket-lugs l9, H, the hookshaft I5 carries a spiral pinion 23 having its hub 23' secured upon said shaft by a set-screw 24. The upper end of the pinion-hub 23' engages a ball thrust-bearing'25 set into the opening l9 of the bracket-lug l6 below the ball-bearing 20; said thrust-bearing 25 being preferably spaced from the shaft l5 and being adapted to absorb upward thrusts imposed upon said shaft by the driving connections therewith. The pinion 23 is engaged by the usual spiral driving gear (not shown) carried by the bed-shaft 28; the driving connections for the hook-shaft It! being such that the hook 9 rotates twice for each complete reciprocation of the needle.

The lower end of the hook-shaft l5 terminates within the bushing 22 and is provided with an axial cylindrical opening 21 having a conically downwardly flaring lower end 28. with the upper end of the hook-shaft openin Connected 21 and preferably axially of said opening is the lower end of a substantially straight duct 29 extending upwardly through the hook-shaft l at an inclination to the axis of rotation of said shaft; whereby the upper end ofthe duct 29 is eccentric to said axis. The upper end of the duct 29 is connected by a radial duct 30 in the bottom wall ll) of the hook with a duct 3| provided in the hook side wall H and terminating in the hook raceway l3. The connected ducts 29 and 30 together constitute a centrifugal pump for delivering lubricant to the raceway l3 of the loop-taker.

Set into the shaft-bearing aperture of the bushing 22, below the shaft I5, is the cylindrical base 32 of a tubular reduced stem 33. The stationary stem 33 extends vertically upwardly into the hook-shaft opening 21 to terminate short of the upper end of said opening; said stem 33 being externally provided with a spiral thread 34 suitably related and complemental to the cylindrical inner wall of the shaft-opening 2'! to insure delivery of lubricant upwardly into the centrifugal pump duct 29 upon rotation of the shaft l5.

The stem 33 has a reduced neck 33' between the the raceway l3 and is discharged through the recess 35 and the connected ducts 36 and 37.

When the machine is brought into operation, the rotating cylindrical wall of the shaft-opening 21 cooperates with the stem-thread i l to prevent the lubricant, which is supplied through the bore of the stem 33, from being by-passed and discharged through the ducts 3B and 37!. The shaft-opening 21 and the stem-thread 33 therefore function, in the operation of the machine, as a pump-seal for the by-pass provided in the lubricant-conducting connections between the reservoir and the rotary hook raceway i3. Being thus prevented from being lay-passed, the lubricant is caused to enter the shaft-duct 29. The vertically inclined shaft-duct 29 pumps the lubricant by centrifugal force to the upper end stem-base 32 and the lower end of the stema discharge-aperture 31 provided in the bracket- 1' lug IT. A wick 38 is preferably disposed in the longitudinal bore of the stem 33 to retard the flow of lubricant through said bore and also to prevent the formation of air-bubbles in the stembore.

Connected to the stem-base 32 to deliver lubricant to the longitudinal bore of the tubular stem 33 is one end of a lubricant conduit 39 extending lengthwise of the bed-plate I. At its opposite end, the conduit 39 is suitabl connected to receive lubricant from a drip-feed reservoir 40 of substantial size; said reservoir being disposed above the bed-plate l and being, in the present case, built into the bracket-arm standard 2. Another conduit 4| is similarly connected to the reservoir. 40 to deliver lubricant to the left hand rotary hook. The reservoir 40 is provided with means for manually controlling the quantity of lubricant supplied to conduits 39 and 4|, and for manually shutting off the supply of lubricant; the present reservoir constituting a duplex arrangement of the built-in reservoir illustrated and described in my prior patent application Serial No. 423,429, filed December 18, 1941, to which reference may be had for a more complete understanding of the details of construction of the reservoir. However, it is to be understood that the present invention is not limited to any specific reservoir construction, as conventional sight-feed oil-cup devices may be employed for supplying lubricant to the improved lubricantfeeding device.

The lubricant gravitationally supplied to the bore of the stem'33 in controlled quantity spills from the upper end of said stem and, when the machine is out of operation, dribbles downwardly externally of the stem within the hook-shaft opening 21. Consequently, when the machine is idle, the lubricant is by-passed from delivery to of said duct, from which it is delivered in the usual manner to the thread-carrier raceway iii of the rotary hook. This arrangement has the advantage of insuring an early supply of lubricant to the raceway l3 after the machine is brought into operation, while at the same time controlling the quantity of lubricant delivered.

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

In a sewing machine, a vertically disposed rotary loop-taker shaft provided at the lower end thereof with an axial opening, a loop-taker carried by the upper end of said shaft for rotation therewith and having a thread-carrier raceway, a thread-carrier journaled in said raceway and restrained against rotation with said loop-taker, lubricant-conduit connections between said axial opening of the loop-taker shaft and said raceway, a stationary tubular stem extending upwardly into and complemental to the inner wall of said axial opening of the loop-taker shaft in providing a pump-seal for the lower end of said opening during the operation of the machine, said stem and the wall of said opening providing therebetween a lubricant by-pass permitting drainage of lubricant from the lower end of said shaft when the machine is out of operation, a

. lubricant-supply reservoir, and lubricant-conducting connections with said reservoir for supplying lubricant through the bore of said tubular stem.

2. In a sewing machine, a vertically disposed rotary loop-taker shaft provided at the lower end thereof with an axial cylindrical opening, a looptaker carried by the upper end of said shaft for rotation therewith and having a thread-carrier raceway, a thread-carrier journaled in said raceway and restrained against rotation with said loop-taker, a stationary tubular stem extending upwardly into and complemental to the inner wall of said axial opening of the loop-taker shaft in providing a pump-seal for the lower end of said opening during the operation of the machine, one of the complemental pump-seal members being provided with a spiral thread disposed in close proximity to the other pump-seal member, a lubricant-supply reservoir, lubricant-conducting connections between said reservoir and said tubular-stem for supplying lubricant through the bore of said stem, and lubricant-conducting connections between said opening of the loop-taker shaft and said raceway of the looptaker.

3. In a sewing machine, a vertically disposed rotary loop-taker shaft provided at the lower end thereof with an axial cylindrical opening, a loop-taker carried by the upper end of said shaft for rotation therewith and having a threadasoaccs end thereof with an axial opening, a loop-takercarried by the upper end of said shaft for rotation therewith and having a thread-carrier raceway, a thread-carrier journaled in said raceway and restrained against rotation with said looptaker, a stationary and externally spirally threaded tubular stem extending upwardly into and complemental to the inner wall of said opening of the loop-taker shaft in providing a pumpseal for the lower end of said opening duringthe operation of the machine, means for supplying lubricant through the bore of said stem, a lubricant duct in said shaft extending upwardly from said opening and inclined to the rotationaxis of said shaft, and lubricant-conducting connections between the upper end of said duct and said raceway.

5. In a sewing machine, a vertical-axis rotary loop-taker shaft provided at its lower end with an axial opening and having a longitudinal bore extending upwardly from said opening at an inclination away from the rotation-axis of the shaft, a rotary loop-taker carried by the upper end of said shaft and having a thread-carrier raceway, lubricant-conducting connections between said bore of the loop-taker shaft and said raceway of the loop-taker, a stationary tubular stem extending upwardly into and complemental to the inner wall of said opening of the looptaker shaft in providing a pump-seal for the lower end of said opening during the operation of the machine, said stem and the wall of said opening providing therebetween a lubricant bypass permitting drainage of lubricant from the lower end of said shaft when the machine is out of operation, means for supplying lubricant through the bore of said stem, and a member provided with a lubricant-discharge port, said port being disposed below and connected with said axial opening of the loop-taker shaft.

6. In a sewing machine, a vertically disposed rotary loop-taker shaft provided at the lower end thereof with an axial opening, a loop-taker carried by the upper end of said shaft for rotation therewith and having a thread-carrier raceway, a thread-carrier journaled in said raceway and restrained against rotation with said loop-taker, a stationary tubular stem extending upwardly into and complemental to the inner wall of said opening of the loop-taker shaft in providing a pump-seal for the lower end of said opening during the operation of the machine, means for supplying lubricant longitudinally through the bore of said stem, and centrifugal-pump means connected with said opening and having lubricantconducting connections with said raceway.

7. In a sewing machine; a vertically disposed rotary loop-taker shaft provided at the lower end thereof with an axial opening, a loop-taker carried by the upper end of said shaft for rotation therewith and having a thread-carrier raceway, a stationary tubular stem extending upwardly into and complemental to the inner wall of said opening of the loop-taker shaft in providing a pump-seal for the lower end of said opening during the operation of the machine, said opening having lubricant-conducting connections with said raceway, and said stem and the wall of said opening providing therebetween a lubricant bypass permitting drainage of lubricant from the lower end of said shaft when the machine is out of operation, and means for gravitationally supplying lubricant through the bore of said stem.

8. In a sewing machine, a vertically disposed rotary loop-taker shaft provided at the lower end thereof with an axial opening, a loop-taker carried by the upper end of said shaft for rotation therewith and having a thread-carrier raceway, a stationary tubular stem extending upwardly into and complemental to the inner wall of said opening of the loop-taker shaft in providing a pump-seal for the lower end of said opening during the operation of the machine, said opening having lubricant-conducting connections with said raceway, and said stem and the wall of said opening providing therebetween a lubricant bypass permitting drainage of lubricant from the lower end of 'said shaft when the machine is out of operation, a wick filling the bore of said tubular stem, and means for gravitationally supplying lubricant through the wick-filled bore of said stem.

9. In a sewing machine, a loop-taker supporting. bracket, a bearing-bushing carried by said bracket, a loop-taker shaft journaled in said bearing-bushing for rotation about a vertical axis, said shaft having the lower end thereof terminating within said bushing and provided with an axial opening, an externally spirally threaded tubular stem extending upwardly into said axial opening of the loop-taker shaft and complemental to the inner wall of said opening in providing a pump-seal for the lower end .of said opening during the operation of the machine, said stem having the base thereof secured in said bushing below said shaft, a loop-taker carried by the upper end of said shaft and provided with a thread-carrier raceway having lubricant-conducting connections with said opening, and means for supplying lubricant through the bore of said tubular stem.

10. In a sewing-machine, a loop-taker supporting bracket, a bearing-bushing carried by said bracket and provided with a lubricant-discharge port, a loop-taker shaft journaled insaid bearing-bushing for rotation about a vertical axis, said shaft having the lower end thereof terminating within said bushing and provided with an axial opening, a loop-taker carried by the upper end of said shaft and provided with a threadcarrier raceway, a tubular stem extending upwardly into said axial opening of the loop-taker shaft and complemental to the inner wall of said opening in providing a pump-seal for the lower end of said opening during the operation of the machine, said stem having a base fitted in said bushing in spaced relation to the lower end of said shaft and below the level of said discharge port of the bushing, means for supplying lubricant through the bore of said tubular stem, and means for conducting lubricant from said opening to said raceway of the loop-taker.

11. In a sewing machine having a frame including a. horizontally disposed work-support, in combinatfon, a vertically reciprocatory needle, a looptaker supporting bracket disposed below said work-support, a bearing-bushing carried by said bracket and provided with a lubricant-discharge port, a loop-taker shaft i urnaled in said bearingbushing for rotation about an axis substantially parallel to the path of needle-reciprocation, said shaft having the lower end thereof terminating within said bushing and provided with an axial opening, a loop-taker carried by the upper end of said shaft and having a thread-carrier raceway, a wick-filled tubular stem extending upwardly into said axial opening of the loop-taker shaft and complemental to the inner wall of said opening in providing a pump-seal for the lower end of said opening during the operation of the machine, said stem having the base thereof secured in said bushing, and said stem being formed to provide in the bushing a lubricant-collection recess disposed below said pump-seal and open to said discharge port, a lubricant-reservoir disposed above said work-support, a conduit connected to said reservoir for gravitationally supplying lubricant through the bore of said tubular stem, and means including a centrifugal pump for conducting lubricant supplied through said stem to said raceway of the loop-taker.

12. In a sewing machine, a vertical-axis rotary loop-taker having a thread-carrier raceway, said loop-taker having a lubricant-duct leading to said raceway, a lubricant-supply reservoir disposed above the level of said loop-taker and having lubricant-conducting connections with said lubricant-duct of the loop-taker, said lubricant-conducting connections including a lubricant by-pass effective when the machine is out of operation for diverting lubricant from delivery from said reservoir to said lubricant-duct of the loop-taker, and means for rendering said by-pass functionally ineffective when the machine is brought into operation.

13. In a sewing machine, a vertically disposed rotary shaft having a longitudinal bore, a looptaker carried by the upper end of said shaft for rotation therewith and having a thread-carrier raceway, a thread-carrier journaled in said raceway and restrained against rotation with said loop-taker, a lubricant-supply reservoir disposed above the level of the loop-taker, lubricant-conducting connections between said reservoir and said shaft bore, said connections including a lubricant by-pass effective when the machine is out of operation to divert the lubricant from passing through said bore, means brought into action upon operation of the machine for rendering said by-pass functionally ineffective, and lubricantthereof with an axial opening, a loop-taker carried by the upper end of said shaft and having a thread-carrier raceway, lubricant-conduit connections between said axial opening of the looptaker shaft and said raceway, a lubricant-supply reservoir disposed above the level of said loop taker, lubricant-conducting connections with said reservoir for delivering lubricant into said axial opening of the loop-taker shaft, said axial opening comprising a lubricant by-pass effective when the machine is out of operation for divcrting lubricant from delivery from said reservoir to said raceway, and means rendered effective upon operation of the machine for functionally closing said by-pass.

15. In a sewing machine, a vertically disposed rotary loop-taker shaft provided at the lower end thereof with an axial opening, a loop-taker carried by the upper end of said shaft and having a thread-carrier raceway, lubricant-conduit connections between said axial opening of the looptaker shaft and said raceway, a lubricant-supply reservoir disposed abovethe level of said looptaker, lubricant conducting connections with said reservoir for delivering lubricant into said axial opening of the loop-taker shaft, said axial opening comprising a lubricant by-pass effective when the machine is out of operation for diverting lubricant from delivery from said reservoir to said raceway, and a pump-seal rendered effective for functionally closing said by-pass when the machine is brought into operation.

16. In a sewing machine, a vertical-axis rotary shaft having at its lower end an axial opening and having a longitudinal bore extending upwardly from said opening at an inclination to the axis of rotation of said shaft, a loop-taker carried by the upper end of said shaft for rotation therewith, said loop-taker having a thread-carrier raceway, a stationary tubular stem extending upwardly into said axial opening of the rotary shaft, means for supplying lubricant through said stem, means effective during rotation of said shaft for feeding lubricant, supplied through said stem, upwardly into the inclined bore of the shaft, and lubricant-conducting connections between the upper end of said bore and said raceway.

FRANK PARRY.

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