US2762325A - Hook lubrication system for sewing machines - Google Patents

Description

Sept. 11, 1956 A. N. HALE ETAL HOOK LUBRICATION SYSTEM FOR SEWING MACHINES 5 Sheets-Sheet 1 Filed Dec.

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HOOK LUBRICATION SYSTEM FOR SEWING MACHINES Filed Dec. 29, 1955. 5 Sheets-Sheet 2 imnu Magi/4 WW Y 684 681063 66 Sept. 11, 1956 A. N. HALE ETAL 2,762,325

HOOK LUBRICATION SYSTEM FOR SEWING MACHINES Filed Dec. 29, 1953 5 Sheets-Sheet 5 Sept. 11, 1956 H E A 2,762,325

HOOK LUBRICATION SYSTEM FOR SEWING MACHINES Filed D60. 29, 1953 5 Sheets-Sheet 4 IFIG.I8

Sept. 11, 1956 A. N. HALE EIAL 2,762,325

HOOK LUBRICATION SYSTEM FOR SEWING MACHINES Filed Dec. 29, 1953 5 Sheets-Sheet 5 HOOK LUBRTCATIGN SYSTEM FOR SEWING MACHINES Arthur N. Hale, Park Ridge, and Raymond T. Smith, McHenry, Ill., assignors to Union Special Machine Company, Chicago, 111., a corporation of Illinois Application December 29, 1953, Serial No. 400,927 8 Claims. (Cl. 112-256) This invention relates to sewing machines and more particularly to sewing machines having a horizontal axis rotary hook. It is concerned particularly with the lubrication of the hook raceway of such a machine.

In sewing machines of the type used industrially and intended for the production of lockstitches it has long been a problem to provide adequate lubrication of the raceway of the rotary hooks, without providing such an excess of lubricant that the work being stitched will be soiled by excess lubricant thrown from the revolving component of the hook onto the work or the threads which enter into the formation of the seam. The hooks in such machines are usually revolved at a high speed, e. g. 8,000 R. P. M. when stitches are to be formed at the rate of 4,000 per minute. It is the desire to operate such machines at even a higher speed and the hook is required to rotate at double the speed of stitch formation. At such high speeds it is difiicult to insure adequate lubrication, at all times, of the usual raceway provided between the rotating and stationary components of the hook, without providing an excessive amount of lubricant, at times, which will soil the work and be wasteful of the lubricant.

An object of the present invention has been to provide a hook lubrication system which will insure adequte lubrication of the hook raceway at all times and will avoid the delivery of an objectionable excess of lubricant under any conditions encountered in the normal use of the machine.

In accordance with the foregoing object, an important feature of the invention is the provision of a reservoir for the lubricant supplied to the hook raceway which is capable of supplying lubricant by gravity to the hook raceway. Means are provided, however, for readily cutting off such supply of lubricant by gravity to the raceway, this means being associated with the plug or other means associated with thelubricant reservoir for providing access to the latter to refill the same. The arrangement is such that when the reservoir is to be refilled, the removal of the plug or the like will automatically shut oi the delivery of lubricant from the reservoir to the raceway. The arrangement is also such that the plug may be adjusted, without removal thereof, to shut off delivery of lubricant from the reservoir to the raceway, whenever desired, or to regulate the rate of supply of the lubricant to the raceway.

A more specific feature of the invention is the provision of means whereby the supply of lubricant from a reservoir to the hook raceway is normally shut off but may be rendered effective to any extent desired by appropriate adjustment of the plug or means for rendering the reservoir accessible for the introduction of a new quantity of lubricant thereto.

A further specific feature is the provision of the filling opening and the plug or other closure means therefor in a member which serves to secure the reservoir to the under surface of the work supporting member of the machine fram Another important feature of the invention is the provision of means within the body of the hook itself which will prevent the delivery of a slug of oil, which may have accumulated at some point in the system, to the hook raceway. Such a slug of oil delivered to the raceway, for example upon the commencement of operation of the machine after it has remained idle for a period of time, would give rise to the work soiling difiiculties which the present invention is intended to overcome.

Other objects, features and advantages of the invention will appear from the detailed description of an illus-v trative form of the invention which will now be givenin conjunction with the accompanying drawings, in which: Fig. 1 is a longitudinal, vertical sectional view through a lockstitch machine embodying the invention;

Fig. 2 is a bottom plan view of the machine with certain parts removed and others broken away and shown in section for clearer illustration;

Fig. 3 is an enlarged, vertical sectional view of a portion of the base of the frame and a hook oil reservoir embodied in the machine, together with associated parts;

Fig. 4 is an exploded perspective view of certain parts embodied in the hook oil reservoir assembly;

Fig. 5 is a view partly in plan and partly in horizontal section showing certain details of the hook oil reservoir;

Fig. 6 is an enlarged longitudinal, sectional view through the rotary hook and a portion of the hook shaft embodied in the machine;

Fig. 7 is a longitudinal, sectional view through the hook shaft of the machine;

Fig. 8 is an enlarged transverse, sectional view through the hook shaft of the machine along the line 8-8 of Fig. 7;

Fig. 9 is a plan view of a core pin or rod mounted within the hook shaft;

Fig. 10 is a view similar to Fig. 6 showing a modified assembly of the rotating hook and the hook shaft;

Fig. 11 is a detail view, in perspective, showing a lubricant control element embodied in the assembly of Fig. 10; and

Fig. 12 is a detail view, in perspective, of a modified,

in the patent to Christensen and Rubel, No. 2,113,572,

granted April 12, 1938, and the patent to Rubel, No. 2,628,583, granted February 17, 1953.

Referring to Fig. 1, the machine is provided with a" main frame having a work supporting base portion 10, a

vertical standard 11, and a horizontally disposed overhanging arm 12 which extends over the work supporting base and terminates in a needle head 12a. Within the overhanging arm there is suitably journalled a shaft 13 which extends through the end wall of the vertical standard 11 and carries at its outer end a combined hand wheel and pulley 14 through which power may be supplied to the machine. Within the needle head the shaft 13 carries a crank 15 which is connected by means of a link 16 with a needle bar 17 mounted for vertical reciprocation within the needle head. This needle bar carries a needle 18 which is arranged for reciprocation between a position above the work support of the base to a position in Which the eye of the needle is below the work support and arranged for cooperation with a rotary hook to be described. Gearing 19 within the vertical standard serves to connect the shaft 13 with a shaft 20 mounted in suitable bearings in the work supporting base. As shown in Fig. 2, the shaft 20 is arranged to drive suitable work' 22 secured to a hook shaft 23. Gear 21 and pinion22 are such that for each revolution of the shaft 20, two

Patented Sept. 11, 1956;

revolutions will be imparted to the hook shaft 23. Shaft receives one revolution for each revolution of the upper shaft 13. Carried by the hook shaft 23, at its left end, is a rotary hook indicated generally at 24. This hook has a rotating component secured to shaft 23 andprovided with a needle loop seizing beak 26. Within thev rotary component of the hook there is mounted a bobbin basket 27 which is held against rotation by the action of a detent or retainer 28 having a projectionwhich cooperates. with a notch or recess 29 provided in the outer face of the bobbin basket. Extending circumferentially most of the way around the periphery of the bobbin basket. is a rib 30 arranged to have bearing ongagernent with a groove or raceway 31 provided in the inner surface of the cup like portion of the rotary con ponent of the'hook assembly.

As hereinabove' indicated, the present invention is concerned' with the provision of means for supplying lubricant to the raceway 31 in amounts sufficient to meet the requirements thereof without, however, bringing about the delivery of excess lubricant at any time which may soil the work or the stitching threads. For the delivery of lubricant to the raceway, the hook body is provided with a small bore or passage 32 which extends from the raceway to a radially extending bore or passage 33 that communicates at its inner end with a substantially cylindrical pocket 34 formed wihin the hub portion of the rotating component 25 of the hook. This pocket is formed betweenan enlarged head 35 at the end of the hook shaft, which fits tightly within the hub of the rotating component 25, and a closure disk 36 in the base of the hook body. The closure disk 36 is provided with a small central aperture 37 for air venting purposes. its location is such that the lubricant will not be discharged through it but air is admitted to the pocket 34- to prevent the deyeloprnent of an air lock.

Hook shaft 23 has a bore, extending throughout its length, within which is snugly fitted arod 38. The friction between the rod and the inner wall of the hook shaftis such that these parts will rotate together. Extending longitudinally of the rod 38 is a shallow and narrow groove 39 adapted to deliver the desired amount of lubricant from a source of supply at the right end of they shaft (Fig. 7). Groove 39 is slightly deeper at its right end, as indicated at 40, to facilitate introduction of lubricant into the bore of the shaft for delivery along the groove to the pocket 34. Rod 38 is provided with a reduced stern portion 41 at its right end which fits into an-opening 42 in the shaft which forms an extension of the axial bore in the shaft 19 but is of reduced diameter. Adequate clearance is provided between the stem 41- and the opening 42 to permit the passage of at least the maximum amount of lubricant desired for the hook raceway. At the extreme right end of the shaft a counterbore 43 is provided as an extension of the opening 42 to. facilitate the delivery of lubricant to the latter.

The right end of the hook shaft 23 is journalled in a bushing 44 (Figs. 2 and 3) carried by a downwardly extending portion of the base it) of the frame. The end of the hook shaft extends into an enlarged opening 44a in the bushing. To prevent the leakage of oil around the portion of the hook shaft which is within the bushing 44, a washer 45 mounted on the shaft cooperates with the end of the bushing 44. A packing ring 46 formed of rubber, felt, or other suitable compressible material, is provided between the washer 45 and the inner end of the hub of the pinion 22. At the opposite end of the bushing 44 there is inserted a tapered nipple element 47 having a shoulder which bears against a gasket 48 the opposite face of which engages the adjacent end of the bushing 44-. Nipple 47 is carried by a lubricant reservoir 49. the main body of which is preferably die cast. The nipple may be incorporated in the main body in the. course of casting the latter or it may be inserted with a tight fit afterwards. Reservoir 49 is secured to the under surface of the work supporting portion of the frame by means of a hollow, screw threaded plug or sleeve 50. This has screw threaded engagement, as indicated at 51, with an opening in the top of the reservoir, and when the parts are assembled, as shown in Fig. 3, it serves to retain the reservoir firmly against the under face of the work support 10. A gasket 52 is preferably provided between the head of the plug 50 and the upper surface of the work support. An opening 53 in the latter, through which the plug extends, is of somewhat larger diameter than the outside diameter of the plug to facilitate positioning of the reservoir so that the nipple 47 is maintained in proper relation to the right end of the hook shaft and serves to retain the gasket 48 against the end of the bushing 44. An upwardly extending projection 54 on the top of the reservoir, which also cooperates with the under face of the work support 10, assists in retaining the reservoir in proper position.

A plug 55 having a screw threaded portion 56 which cooperates with screw threads formed internally of the hollow plug 56 may be removed whenever it is desired to refill the reservoir. As will be explained, this plug also serves as a means for regulating the supply of lubricant from the reservoir to the hook raceway. At its right end (Fig. 3) the reservoir is closed by a plate 57 which is held against a gasket 58 by means of a series of screws 59 (see also Figs. 4. and 5). A plug 60, carried by the plate 57, isprovided with an opening or recesslla which receivesthe end of a rod 61 the opposite end of which is tapered, as indicated at 62, to cooperate with a tapered opening extending through the nipple 47. Within the reservoir there is secured to the rod 61 a plate 63 having a downwardly extending projection 63a arranged for sliding engagement with the bottom of the reservoir. A spring 64 surrounding the rod 61, and compressed between the inner end of the plug 66 and the adjacent end 65 of the plate 63, serves to urge the latter and the rod 61 toward the left (Fig. 3). Thus, normally the tapered end 62 of the rod 61 is urged into a position to close off the passagethrough the nipple 47 which communicates with the bore of the hook shaft. However, the rod 61 may be retracted against the action of the spring turning the plug 55 to cause the lower conical or tapered end 66 thereof to cooperate. with the wall of an opening 67 through the plate 63. Depending upon the extent to which the plug 55 is turned in the direction to cause the tapered end thereof to move downwardly, the rod 61 Will be retracted to a greater or less extent, thus regulating the discharge.-

of lubricant from the reservoir. On removal of the plug- 55 to refill thev reservoir, the spring 64will become. automatically effective to close oif the tapered opening through the nipple 47.

level of the lubricant within the reservoir. As shown in Figs. 3. and 5, the gauge for this purpose may simply. be a plug 68, formed of glass or Lucite, or the like, which extends through the top of the reservoir into the interior of the latter to a point adjacent its bottom. The lower end of this plug is provided with an inclined surface 68:: having a series of grooves or lines 68b at different levels. These and the level of the lubricant can be seen through the Lucite plug, which preferably extends into, or is positioned below a suitable opening through the work support 10. ofthe frame. This gauge is of the. type. disclosed. in the'patent to Sauer, No. 2,301,460, granted November 10, 1942.

To facilitate the insertion-of the rod 38 in the bore of the. hook shaft 23 and its removal from the bore, the left end of the rod is provided with a screw threaded opening 69. adapted to receive the stem of a suitable tool having a screw threaded end. The left end of the bore in the hook shaft is preferably flared outwardly, as indicated at 70in Fig. 7, to facilitate the proper flow of the lubricant toward the periphery of the pocket 34 as the hook and hook shaft are rotated.

The supply of lubricant to the hook raceway from the reservoir 49 is effected partially by gravity and partially by a slight pumping action created by the construction and arrangement of the several parts. When the machine 1s idle, and particularly if the reservoir 49 is relatively full at this time, it is desirable to close off the passage through the nipple 47 to prevent the delivery by gravity of further lubricant from the reservoir to the bore of the hook shaft. This may be accomplished simply by backing off the plug 55 to an extent suificient to permit the spring 64 to urge the rod 61 into the closing position.

Referring now to Figs. 10, 11 and 12, there is shown a slight modification of the hook and hook shaft assembly which achieves an additional purpose. In this modified arrangement the parts are substantially the same as shown in Fig. 6 and bear similar reference numerals with the addition of an a. The difference between the two arrangements is the provision, in the Fig. 10 embodiment, of an annular element 71 within the pocket 34a in the hub of the rotating component of the hook. This annular member 71 is formed of felt or similar porous material which permits the passage of lubricant through the same into the channel 33a but prevents the delivery of a large slug of oil from the pocket 34a into the channel 33a. It has been found that without the provision of a member of this character a certain amount of lubricant sometimes accumulates in the bore of the hook shaft and drains or is otherwise delivered into the pocket in the hook body. This may occur, for example, if the operator fails to turn the plug 55 to cause closing of the passage through the nipple 47 when the machine is left idle for a time. When it does occur and the machine is started up, after an idle period, a slug of oil will be thrown through the passages 33 and 32 to the hook raceway with consequent soiling of the work or the stitching threads.

In lieu of the annular element 71 there may be inserted in the pocket 34a of the hook body a disklike member 72 (Fig. 12) formed of similar porous material. If such a disklike member is employed it should have sufncient porosity to permit the passage of enough air through the opening 37a in the base of the hook body to prevent the system from becoming air locked.

While an illustrative form of the invention has been described in considerable detail and certain variations have been suggested, it will be understood that other changes may be made in the construction and arrangement of the several parts without departing from the general principles and scope of the invention.

What is claimed is:

1. In a lock stitch sewing machine having a base with a work supporting surface and a horizontally disposed hook shaft journaled in said base, a hook mounted on said shaft, said hook having a rotary component and a stationary component, one of said components having a rib thereon and the other component having a raceway for said rib, means for lubricating said raceway which comprises a reservoir beneath said work supporting surface adapted to retain lubricant at a level above the axis of said hook shaft, said hook shaft having an axially extending bore arranged to receive lubricant from said reservoir and deliver the same to said raceway, said reservoir having a filling opening accessible through said work supporting surface, removable means for closing said filling opening, and means rendered effective by removal of said removable means for preventing the delivery of lubricant from said reservoir to the bore of said hook shaft.

2. In a lock stitch sewing machine having a base with a work supporting surface, a horizontally disposed hook shaft journaled in said base, a hook mounted on said shaft, said hook having a rotary component and a stationary component, one of said components having a rib thereon and the other component having a raceway for said rib, means for lubricating said raceway which comprises a reservoir beneath said work supporting surface adapted to retain lubricant at a level above the axis of of the hook shaft upon adjustment of said removable means.

3. In a lock stitch sewing machine having a horizontally disposed hook shaft, a hook mounted thereon, said hook having a rotary component and a stationary component, one of said components having arib thereon and the other component having a raceway for said rib, means for lubricating said raceway which comprises a reservoir adapted to retain lubricant at a level above the axis of said hook shaft, said hook shaft having an axially extend ing bore throughout the length of said shaft arranged to receive lubricant at one end thereof from said reservoir and deliver the same to said raceway, said reservoir having a filling opening, removable means for closing said filling opening but adapted upon removal to enable filling of said reservoir, said removable means being adjustable to different closing positions in relation to said filling opening, and means controlled by said removable means in accordance with the adjustment thereof for regulating the delivery of lubricant from said reservoir to the bore of the hook shaft, said means controlled by said removable means serving automatically to prevent delivery of lubricant from said reservoir to said bore upon removal of said removable means.

4. In a lock stitch sewing machine having a base with a work supporting surface, a horizontally disposed hook shaft journaled in said base, a hook mounted on said shaft, said hook having a rotary component and a stationary component, one of said components having a rib thereon and the other component having a raceway for said rib, means for lubricating said raceway which comprises a reservoir beneath said work supporting surface adapted to retain lubricant at a level above the axis of said hook shaft, said hook shaft having an axially extending'bore arranged to receive lubricant from said reservoir and deliver the same to said raceway, said reservoir having an outlet communicating with said bore of the hook shaft, a valve in said outlet adapted to close the same, said reservoir having a filling opening remote from said outlet and accessible through said work supporting surface, a removable closure for said filling opening, said closure being shiftable to different closing positions in relation to said filling opening, and means controlled by said closure for closing said valve upon removal of said closure and for adjusting said valve to regulate the discharge of lubricant through said outlet upon shifting of said closure to said different closing positions.

5. In a lock stitch sewing machine having a horizontally disposed hook shaft, a hook mounted thereon, said hook having a rotary component and a stationary component, one of said components having a rib thereon and the other component having a raceway for said rib, means for lubricating said raceway which comprises a reservoir adapted to retain lubricant at a level above the axis of said hook shaft, said hook shaft having an axially extending bore throughout its length arranged to receive lubricant from said reservoir and deliver the same to said raceway, said reservoir having outlet means provided with a horizontally directed orifice communicating with said bore at one end of the hook shaft, a spring urged rod having a tapered end cooperating with said orifice and normally urged into a closing position in relation thereto, said reservoir having a vertically directed filling opening remote from said orifice, and a removable closure for areas-2s 7- said filling opening cooperating with. said rod to shift the. same, out of said closing position,

6. In. a lock stitch sewing machine having-a horizontally disposed hook shaft, a hook mounted thereon, said hook having a rotary component and a stationary component, one of said components having a rib thereon and the other component having a raceway for said rib, means for lubricating said raceway which comprises a reservoir adapted to retain lubricant at a level above the axis of said hook shaft, said hook shaft having an axially extending bore arranged to receive lubricant from said reservoir and deliver the same to said raceway, said reservoir having outlet means provided with an orifice communicatingwith said bore of the hook shaft, a spring urged rod having a tapered end cooperating with said orifice and normally urged into a closing position in relation. thereto, said. reservoir having a filling opening, and a. removable closure for said filling opening cooperating with said rod to shift the same out of said closing position, said closure being adjustable to different positions in which it closes said filling opening, said rod being shifted to differentextents to regulate the discharge of lubricant through said orifice upon adjustment of said closure to said different positions.

7. In a lock stitch sewing machine having a hori: zontally disposed hook shaft having an axially extending bore therein, a hook mounted thereon, said hook having a rotary component and a stationary component, one of said components havinga rib thereon and the other component having a raceway for said rib, means for lubrieating said raceway which comprises means in said rotary component providing a lubricant receiving pocket communicating with the bore in said shaft and a passage therefrom for the delivery of lubricant to said raceway, said pocket being of larger diameter than said bore, said rotary component having an air passage communicating, with said pocket adjacent the center thereof, a circular porous element in said pocket having an axial dimension less than its diameter extending over the inlet to said lubricant delivery passage, said porous element being'adapted to enable the relatively free passage-of air therethrough from aid air pa sage, a res rv ir.- ad p o re inlubrican at a level above the axis of said hook shaft, said: hook shaft having, an axially, extending bore arranged, to receiye lubricant, from said, reservoir and deliver the same tov said pocket, said, reservoir. having a filling opening,

removable means. for. closing said filling opening, andmeans rendered effective by removal of said removable means for preventing the delivery of lubricant from. said reservoir: to the bore ofsaid hook shaft.

8. In a lock stitch sewing machine having a horizontally disposed hook shaft having an axially extendingbore therein, a hook mounted thereon, said hook having a rotary component anda stationary component, oneof said'componentshaving a rib thereon and the other cornponent' having a. raceway for said rib, means for lubrieating said raceway which comprises means in said rotary component providing a substantially cylindrical lubricantreceiving pocket therein in axial alignment withsaid shaft, said pocket, being of; larger diameter than said bore, a passage extending from. said pocket to said raceway for delivery of lubricant to the latter, an annular member formed of porous material extending around the wall of said pocket and over the inlet to said passage, said rotary component having an opening. therein for the delivery of v air to substantially the center of said annular member,

References li tedinrthe file of this patent UNITED STATES PATENTS 1,745,216 Horger V f n Ian, 28, 1930 2,098,904 Waterman Nov. 9,, 1937 2,385,288" Le Vesconte et a1. Sept. 18', 1945 2,395,653 Attwood' Eeb. 2 6, 1 946 2,628,583 .Rubel' p Feb. 17, 1953

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