US2758557A - Loopers and looper throw-outs for chain-stitch sewing machines - Google Patents

Description

E. A. MUECKE Aug. 14, 1956 2,758,557 LOOPERS AND LOOPER THROW-OUTS FOR CHAIN-STITCH SEWING MACHINES 3 Sheets-Sheet 1 Filed Dec. 8, 1954 INVENTOR. Edward A. Muecke WITNESS Aug. 14, 1956 Filed Dec. 8, 1954 W/TNESS E. A. MUECKE LOOPERS AND LOOPER THROW-OUTS FOR CHAIN-STITCH SEWING MACHINES 3 Sheets-Sheet 2 Fig.2.

INVENTOR.

- Edward A.Muecke ATTORNEY Aug. 14, 1956 E. A. MUECKE 2 7 LOOPERS AND LOOPER THROW-OUTS FOR CHAIN-STITCH SEWING MACHINES Filed Dec. 8, 1954 3 Sheets-Sheet 3 mmnnnnn IN VEN TOR.

Edward A. Muecke W/TNESS BY ATTORNEY United States Patent LOOPERS AND LOOPER THROW-OUTS FOR CHAIN-STITCH SEWING MACHINES Edward A. Muecke, Linden, N. 1., assignor to The Singer Manufacturing Company, Elizabeth, N. J., a corporation of New Jersey This invention relates to sewing machines and more particularly to chain-stitch sewing machines having a plurality of synchronously driven loopers that can easily be positioned to facilitate threading, and one of the principal objects of the present invention is the provision of an improved looper mechanism as well as an improved looper throw-out mechanism.

A further object'of the invention is the provision of an improved mechanism for synchronously driving a pair of loopers and at the same time providing an improved means whereby the operator can selectively move the loopers from a normally inaccessible operating position to a position easily accessible for threading.

Another object of the invention is the provision of an improved means for lubricating a looper mechanism.

A still further object of the invention is the provision of an improvedlooper mechanism arranged sothat the position of the loopers can easily be adjusted to' correspond with changes in the gauge or spacing of the needles.

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

Fig. 1 is a fragmentary, Vertical, longitudinal sectional view of a portion :of a chain-stitch sewingmachine' embodying the looper throw-out mechanism of this invention;

Fig. 2 is a bottom plan view, with a portion insection, of the sewing machine shown in Fig. 1;

Fig. 3 is a fragmentary elevational view taken on the line 3-3 of Fig. 1, the dash-dash lines showing parts of the looper throw-out moved to the threading position;

Fig. 4 is a sectional plan view taken along the line 4-4 of Fig. 1;

Fig. 5 is an elevational sectional view taken substantially along the line 5-5 of Fig. 1'; and

Fig. 6 is an exploded perspective view of portions of the looper throw-out mechanism.

Referring. now in detail to the drawings, the illustrated embodiment of the invention is shown asapplied to'a sewing machine which in some respects is similar to'the one shown in the United States Patent No. 2,441,931, issued May 18, 1948, assigned to- The Singer Manufacturing Company.

The sewing machine, which incorporates the improved looper and the-improved looper throw-out mechanism of the present invention, comprises a' bed-plate provided with an access opening closed by a removable cover 16, an" overhanging bracket-arm-head" 17 that supports a presser-bar 18 which in turn supports a presser-foot. 19, and aneedle-bar 20 which in' turn supports a plurality of needles 21-21. Below the bed-plate 15' are supported portions of the sewing machine comprising a rotary drive shaft 22-having a crank 23 and an eccentric (not shown, but which is illustrated in United States Patent No. 2,441,931 supra) by which, respectively, the required endwise reciprocatory or loop-seizing andloopshedding'movements, as well as the vibratory or so-called needle avoiding movements are imparted to a pair of loopers 24 and 24. Each looper is mounted on its own iooper- carrier 26 or 26, and each looper-carrier comprises a pivotal'sleeve 25 or 25 and a looper-carrier- arm 30 or 3%). Each looper-carrier 26 or 26' is, by means of the sleeves 25 or 25', pivotally supported on its own lcoper-carrier-support, these being designated generafly by the numerals 27' and 27'.

The endwise reciprocatory movement of the loopers 24-24 is controlled by the crank 23 through the medium of a pitman' 28, rock- arms 29 and 29 journaled on a stud 3'1, and through a link 32 connecting the rockerarm 29, with the looper-carrier 26. The second loopercarrier 26 is connected to the first looper-carrier 26 by means of a link 33 (Fig. 1) thereby causing the two looper- carriers 26 and 26 to rock in. unison and their loopers 24-24 to reciprocate in synchronism.

Lateral or sidewise vibrating movements of the loopers are effected through the medium of an eccentric actuating fork 34 (Fig. 2) and a tubular or hollow rock-shaft 36 having a bore 35, the shaft 36 extending longitudinally of the bedplate 15 and said shaft being journaled in bushings 37 and 38 fitted Within a bearing support 39. The support39'forms a part of a bracket 41 depending from theunderside of the bedplate 15 and thus the support 3% carries the rock-shaft 36, one portion of which supports a looper throw-out device designated by the numeral 42.

The looper throw-out device 42 (Figs. 3, 4 and 6) includes asubstantially cylindrical plate or collar 43 positioned at a location approximately three-fifths of the distance from one end 44 of the rock-shaft 36 to the other end 46 thereof. This plate 43 is provided with an axially extending'latch-notch 47 and a flat 48 adjacent to i one side of the notch 47. The hollow shorter end 46 of the rock-shaft 36 turnably supports a hollow looper-support sleeve 49 (Fig. 4), which may selectively be connected toor disconnected from the rockshaft36. For this purpose the sleeve 49' (Fig. 6) carries a plate 51 at the endrof the sleeve 49 which is adjacent to the plate 43. Fromone face 52 of this plate 51 protrudes a block 53 and at one end of the block 53 there further protrudes a visor-like member 54, the outer surface of the visor-like member 54' being provided with a spring-receiving recess 56 (Fig. 4). A yoke 57, which has two legs straddling the aforesaid block 53 and a convex end 58 connected thereto by screws 59-59, is slidably carried on the block 53, and positioned between the plates 43 and 51. The convex end 58 of the yoke 57 is biased away from the previously mentioned visor-like member 54 by means of a helical compression spring 61. One end ofv the spring 61 enters the recess 56 in the visor-like member 54 andthe other end of the spring 61 enters a recess 62 formed in the convex end 58. The end of the yoke 57 remote from the convex end 58 carries a protruding latch-lug 63, which is of such size as to enter the axially extending latch-notch 47 formed in the plate 43. When the yoke 57 is moved in a direction to compress the spring. 61, the latch-lug 63 moves out of the latch-notch 47 to' such an extent that, by turning the plate 51, the blocki53 and the yoke- 57 as a unit, the latch-lug 63 may bepositioned to overlie the flat 48 thereby holding the spring 61 compressed.

The looper-support-sleeve 49 (Fig. 4) carries the previously mentioned looper-carrier-supports 27 and 2'7 and each looper-carrier-support comprises looper- carrier support bracket 64 or 64 and a loopercarrier-support rock- pin 67 or 67 having bores 65 or 65'. Each looper-carrier-support bracket 64-64 is held to the sleeve 49 by a split member formed integral with each bracket and forced closed by screws 66-66. The rockpins 67-67 pivotally' mount the looper-carriers 26-26 Patented Aug. 14, 1956 respectively a which, as previously stated, support the conventional loopers 24-24. The looper-carriers 26-26 are caused to pivot in unison about the rock-pins 67-67 by means of the connecting link 33, opposite ends of which are pivotally connected to the looper-carriers 26and 26' by means of screws 63 and 68. The looper-carrier 26 is connected, by means of a ball and socket joint 69 and longitudinally adjustable connection 71 to one end of the previously mentioned link 32.

In order that the loopers 24 and 24 may be adjusted to correspond with changes in the gauge or spacing between the needles 21-21, the looper-carrier- support brackets 64 and 64 are spaced (Figs. 1 and 2) from one another by means of a cylindrical spacing sleeve 72. The looper-carrier-support bracket 64 is spaced from plate 51 by means of a cylindrical spacing sleeve 73, and the loopencarrier-support bracket 64' is spaced from the terminal of the rock-shaft 36 by means of a cylindrical sleeve 74. The distance between and the location of the looper-carrier-support brackets 64-64 and the spacing between and the location of the loopers 24-24 can be adjusted and varied by removing the sleeves 72, 73 and 74 and substituting sleeves having diflerent axial lengths. It will be noted that for the purpose of illustration the sleeves 72A, 73A and 74A are shown in Fig. 4 as having different axial lengths than the corresponding sleeve '72, 73 and 74 shown in Figs. 1 and 2. The sleeves 72, 73 and 74 or the sleeves 72A, 73A and 74A as well as the looper-carrier- support brackets 64 and 64 are properly positioned and held on the looper-support sleeve 49 by means of a terminal screw 76 which is threaded into the end of the rock-shaft 36. It will be understood that the link 33, which is shown in Figs. 1 and 2, will not be long enough when the sleeves 72A, 73A and 74A shown in Fig. 4 are used. A lengthened link is shown in Fig. 4 as 33A.

The looper throw-out device 42 includes a manually operable unlatching lever 77 which, by means of a screw 73, is pivotally mounted on the free end of a bar 79 carried on the bearing support 39 by means of a split ring 81 that is held closed by a clamping screw 82. The lever 77 is biased to a predetermined position by means of a leaf spring 83 (Figs. 2 and 6), one end of which is held to the support bar 79 by means of a screw 84. The other end of the leaf spring 83 is L-shaped and engages a flattened end 86 of the lever 77. When the lever 77 is moved from the normal position in which it is held by the spring 83, the spring 83 is flexed sufiiciently so that when the lever 77 is released the spring 83 returns the lever 77 to its normal position. The lever 77, at a location between its two ends, carries a screw 87 which rotatably supports a roller 88. When the lever 77 is manipulated, the roller 88 engages the external surface of the convex end 58, thereby moving the yoke 57 against the action of the compression spring 61. This moves the latch-lug 63 out of the latch-notch 47 and makes it possible to turn the looper-support-sleeve 49 and the yoke 57 from the solid line position shown in Fig. 3 to the position shown in dash-dash lines. This moves the loopers 24 and 24 from an inaccessible operating position to an accessible threading position, thereby making it possible to thread the loopers with ease. In this connection it will be noted that turning the looper-support-sleeve 49 and the yoke 57 positions the latch-lug 63 above the fiat 48 and holds the yoke 57 in the extended position and the helical spring 61 compressed. When the loopers 24 and 24- are moved from the accessible threading position to the operative position, the latch-lug 63 snaps back into the latch-notch 47 and assures that the loopers 24-24 will be properly positioned with respect to the needles 21-21.

Lubrication In order that the loopers may be actuated at high speeds and for long periods of time, various parts of the looper 4 mechanism are lubricated by oil under pressure. This oil is supplied from a pump (not shown) to an oil pipe 91 (Fig. 2) which by means of a fitting 92 is connected to an L-shaped oil duct 93 drilled in a member depending from the lower surface of the bed-plate 15. The delivery end (Pig. 1) of the oil duct 93 connects with a bearing groove 94 which in turn communicates through a port 96 and a duct 97 leading to a port 98 formed in the previously described bearing bushing 37. The port 93 is connected by means of a bearing channel 99 with a cavity formed between the two bearing bushings 37 and 38. From the cavity 101 the oil is forced through a pair of radially disposed ports 162-162 formed in the hollow rock-shaft 36 and thence into the longitudinally extending bore 35. The bore at the end 44 of the rock-shaft 36 is closed by an apertured overflow plug 103, the aperture of which permits excess oil to escape and flow back to an oil pan (not shown) located below the bed 15. The oil which does not escape through the apertured plug 103 flows (Fig. 4) toward the other end 46 of the rock-shaft 36. Some of this oil passes through radial ports 104-404 formed in the wall of the rockshaft 36 thereby lubricating the rock-shaft 36 as it rotates in the bearing bushing 38. Another portion of the oil passes through radial ports 106-196 formed in the rocl-:- shaft 36 and thereby enters a cavity 107 formed by two circumferential grooves, one groove being formed in the inner surface of the looper-support sleeve 49 and the other groove being formed in the outer surface of the rock-shaft 36. From the cavity 107 the oil passes through ports 108-108 to an axially extending groove 109 formed in the external surface of the looper-support sleeve 49. From the groove 1439 oil passes into the ends of the bores 65 and 65' of the rock- pins 67 and 67 and thence through ports 111-111 and 111-111 into cylindrical channels 112 and 112' formed in the inner surfaces of the pivotal sleeves 25-25. The cylindrical channels 112 and 112' (one being shown in Fig. 5) respectively connect with axially extending grooves 113-113 likewise formed in the inner surfaces of the pivotal sleeves 25 and 25. Opposite ends of the grooves 113 and 113' are radially extended as indicated at 114-114 and 114'-114'. This assures that the inner cylindrical bore and the two end faces of the pivotal sleeves 25-25 will be properly lubricated. Oil also passes from the grooves 113 and 113 through bores 117-117 (one being shown in Fig. 5) extending longitudinally through the looper-carrier-arms 30-30. Oil passes from the bores 117-117 to bores 113-118 and thence through ports 119-119 and 119-119 formed in the journals which journal the opposed hubs of the previously mentioned connecting link 33, it being noted that the ports 119-119 and 119-119' discharge into grooves 121-121 formed in the said hubs of the link 33. Oil also passes from the bore 117 to a bore 122 and thence through a bore 123 thereby lubricating the engaging surfaces of the ball and socket joints 69 which connects the link 32 with the looper-carrier-arm 30. From this it can readily be seen that all moving parts of the looper mechanism are force lubricated and can thus be operated at high speeds for long periods of time.

Operation The operation of the above described device is apparent from the foregoing, however, the operation will be briefly outlined as follows. The first thing that an operator will do who wishes to thread the loopers will be to remove the cover 16. Then pressing the upper end of the unlatching lever 77 causes the lever to move against the action of the leaf-spring 83 and to carry the roller 88 (which as seen in Fig. 2 is normally out of contact with the convex end 58) into contact With the convex end 58. This moves convex end 58 and the yoke 57 against the action of the helical spring 61 and frees the latch-lug 63 from the latch notch 47. Then the operator moves (Fig, 3) the loopers 24-24 from an inaccessible position to an accessible threading position, and also moves the latch lug 63 above the flat 48. When the lever 77 is released, the lug 63 rests on the flat 48 and the loopers 24-24 remain in threading position. After the loopers 24-24 are threaded, the operator moves the loopers back to the operative position and the latch lug 63 automatically snaps into the latch notch 47.

If the operator wishes to change the gauge between the needles 21 and 21, the position of the loopers 24-24 are changed correspondingly. This is accomplished by removing the terminal screw 76, and loosening the screws 66-66. Then the sleeve 74, the looper-carrier-support 27', sleeve '72, the looper-carrier-support 27 and the sleeve 73 are removed from the looper-support sleeve 49. Thereafter, the looper-carrier- supports 27 and 27 are spaced by difierent sized sleeves, for example, sleeves 72A, 73A and 74A (Fig. 4) being substituted for the sleeves 72, 73 and 74 shown in Figs. 1 and 2. It will,

of course, be understood that sleeves of many different sizes may be used and thus any gauge between the needles 21-21 may be matched by variations in the spacing between the loopers 24 and 24. The length of the link 32 can, of course, be adjusted by varying the adjustable connection 71. It will also be understood that the link 33 may be replaced by the link 33A of dilferent length or the length of the link 33 may, if desired, be made adjustable in the same manner in which the link 32 is adjustable.

Lubrication of the looper mechanism which is accomplished by oil flowing through the hollow bore 35 of the shaft 36 is automatic in its operation. An excess of oil is introduced through the oil pipe 91. Excess oil is discharged through the overflow plug 103 and the rest of the oil lubricates all moving parts of the looper mechanism.

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

1. In a looper mechanism for a chain-stitch sewing machine, a bed-plate for said machine, a rock-shaft supported below said bed-plate, a first plate carried on said rock-shaft, said first plate carrying a latch-member, a looper-support-sleeve journaled on one end of said rockshaft, a second plate carried on said looper-supportsleeve, said second plate carrying a latch-member, means for moving one of said latch-members relative to the plate it is carried by and a manually actuated unlatching lever carried by said bed-plate for moving one of said latch members out of engagement with the other latchmember.

2. In a looper mechanism for a chain-stitch sewing machine, a bed-plate for said machine, a rock-shaft supported below said bed-plate, a first plate carried on said rock-shaft, said first plate being provided with a latchnotch, a looper-support-sleeve journaled on one end of 'said rock-shaft, a second plate carried on said loopersupport-sleeve, a yoke slidable on said second plate, said yoke being provided with a latch-lug adapted to enter said latch-notch in said first plate, and a manually actuated unlatching lever carried by said bed-plate for engaging and moving said yoke and thereby moving said latch-lug out of said latch-notch.

3. In a looper mechanism for a chain-stitch sewing machine, a bed-plate for said machine, a hollow rock shaft supported below said bed-plate, a first plate carried on said rock-shaft and located between opposite ends thereof, said first plate being provided with a latch-notch and a flat, a looper-support-sleeve journaled on one end of said rock-shaft, a second plate carried on the end of said looper-support-sleeve which is adjacent to said first piate, said second plate being provided with a block and a visor-like member, a yoke positioned between said two plates and slidable on said block, said yoke being provided with a latch-lug adapted to enter said latch-notch in said first plate, a helical compression spring positioned between said visor-like member and said yoke and biasing said latch-lug into said latch-notch, and a manually actuated unlatching lever carried by said bed-plate for engaging and moving said yoke against the compression of said spring and thereby moving said latch-lug out of said latch-notch.

4. In a looper mechanism for a chain-stitch sewing machine, a bed-plate for said machine, a hollow rockshaft supported below said bed-plate, a looper-supportsleeve journaled on said rock-shaft, latch means for selectively connecting and disconnecting said looper-supportsleeve and said rock-shaft, a plurality of looper-supportbrackets mounted on said looper-support-sleeve, means for selectively securing said looper-support-brackets to various locations on said looper-support-sleeve, a loopercarrier pivotally mounted on each of said looper-supportbrackets, a looper carried on each looper-carrier, and means for lubricating the moving parts associated with said looper-support-sleeve, said looper-support-bracket and said looper-carrier. a 5. In a looper mechanism for a chain-stitch sewing machine, a bed-plate for said machine, a hollow rockshaft supported below said bed-plate, a first plate carried on said rock-shaft and located between opposite ends thereof, said plate being provided with a latch-notch and a flat, a looper-support-sleeve journaled on one end of said rock-shaft, a second plate carried on the end of said looper-support-sleeve which is adjacent to said first plate, said second plate being provided with a block and a visor-like member, a yoke positioned between said two plates and slidable on said block, said yoke being provided with a latch-lug adapted to enter said latch-notch in said first plate, a helical compression spring positioned between said visor-like member and said yoke and biasing said latch-lug into said latch-notch, a manual unlatching lever carried by said bed-plate for engaging and moving said yoke against the compression of said spring and thereby moving said latch-lug out of said latch-notch, a plurality of looper-support-brackets mounted on said looper-support-sleeve, a rock-pin carried by each of said looper-support-brackets, a looper-carrier-sleeve pivotally mounted on each of said rock-pins, a looper-carrier-arm secured to each of said looper-carrier-sleeves, a looper carried on each looper-carrier-arm, means for pivotally moving said looper-carrier-sleeves and loop-carrier-arms on said rock-pins, and means for lubricating all moving parts of said looper mechanism.

References Cited in the file of this patent UNITED STATES PATENTS 1,915,923 Clayton June 27, 1933 2,397,336 Clayton Mar. 26, 1946 2,441,931 Clayton May 18, 1948 2,630,088 Muecke Mar. 3, 1953

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