US2958299A - Zigzag sewing machines - Google Patents

Description

M. L. WATERMAN ZIGZAG SEWING MACHINES Nov. 1, 1960 2 Sheets-Sheet 1 Filed Aug. 9, 1954 INVENTOR. Max 1.. Waterman ATTORNEY Nov. 1, 1960 M. 1.. WATERMAN ZIGZAG SEWING MACHINES 2 Sheets-Sheet 2 Filed Aug. 9, 1954 INVENTOR.

Max L. Waferman nited rates ZIGZAG SEWENG MACHINES Filed Aug. 9, 1954, Ser. No. 448,484

8 Claims. (Cl. 112-158) This invention relates to improvements in zigzag stitch sewing machines of the laterally vibrating needle type, and it refers particularly to a modification of the needle vibrating control mechanism of the type of zigzag sewing machine forming the subject of the United States patent of M. R. Perla et al., No. 2,756,703, issued July 31, 1956.

The present invention has for its primary object to provide a novel pattern cam controlled mechanism which effects lateral vibrations of the needle.

In the conventional sewing machine of the family machine type it is common to employ a pattern cam for controlling the lateral vibration of the needle to effect a predetermined stitch design. In these machines the frequency of pattern repetition relative to the formation of a predetermined number of stitches is dependent upon the gear ratio existing between the main-shaft of the sewing machine and the shaft on which the pattern cam is carried.

It is the purpose of the present invention to provide a novel pattern member which can be applied to an existing machine, whereby the frequency of pattern duplication can be changed from once for each rotation of the pattern-member-carryiug shaft to one in which more than one revolution of the pattern-member-carrying shaft is needed to traverse the entire periphery of the pattern member.

With the above and other objects in view, as will hereinafter appear, the invention comprises the devices, combinations and arrangements of parts hereinafter described and particularly pointed out in the claims.

In the drawings which illustrate a preferred embodiment of the invention,

Fig. 1 is a front elevational view, partly in section, of a zigzag sewing machine equipped with the present invention.

Fig. 2 is an enlarged sectional view taken along the line 22, Fig. 1.

Fig. 3 is an enlarged horizontal sectional view taken substantially along the line 33, Fig. 1.

Fig. 4 is an enlarged front elevational view, partly in section, of a modified form of guard element which is adapted to retain the pattern member in engagement with its driving sprocket.

Fig. 5 is a rear elevational view of a portion of the bracket-arm of the sewing machine with a part of the frame broken away and the rear cover removed to show the oscillatory pattern-member-follower frame and its connection with the needle-bar-frame vibrating link.

Fig. 6 is a top plan view of that portion of the sewing machine shown in Fig. 5, with the top cover removed and a part of the frame broken away, showing a modified form of pattern member.

Fig. 7 is a vertical sectional view taken along the line 7-7, Fig. 6, showing the manner in which the pattern member is secured to the cross-shaft and the details of the pattern-member-follower.

Fig. 8 is an end elevation of the elements shown in ii 2,958,299 icfi Patented Nov. 1, teen Fig. 7 with a portion in section to show further details of the pattern-member-follower.

'Fig. 9 represents a development of a cam-track applicable to the switch-cam disclosed in Fig. 6.

The present improvement is illustrated in the drawings and hereinafter described as being embodied in a zigzag machine of the type forming the subject of the US. Patent No. 2,756,703, filed October 19, 1953, in the name of Martin R. Perla et al.

Referring to the drawings, the sewing machine illustrated includes a work-suporting bed-plate 10 from one end of which rises a hollow standard 11 of an overhanging bracket-arm 12 terminating at its free end in a head 13. The bracket-arm "12 is preferably formed U-shaped in cross-section and its opened top is closed by a detachable cover-plate 14.

Journaled for rotation in suitable bearings provided in the bracket-arm 12 is a main-shaft 15 carrying at one end a combination hand wheel and driving pulley 16. At the other end the main-shaft is connected in the usual manner to an endwise reciprocatory needle-bar 17 carrying an eye-pointed thread-carrying needle 18. As clearly shown in the above mentioned Perla Patent No. 2,756,703, the needle-bar 17 is journaled for endwise reciprocation in a vibratory needle-bar frame 19 (Fig. 2) pivotally supported at its upper end in the head 13 to provide for lateral swinging movements of the needle 18 in a vertical plane parallel to the axis of rotation of the main-shaft 15. Cooperating with the needle 18 in the formation of lock-stitches is a conventional loop-taker (not shown) which, as shown in the Perla Patent No. 2,756,703, is of the rotary hook variety making two revolutions for each needle reciprocation. Suitable feeding mechanism of the lower four-motion type is provided for advancing work past the needle and cooperating with the work-engaging portion of the lower feeding mechanism is a resser-foot 2t) secured to a conventional spring depressed resser-bar 20'.

Lateral vibrations are imparted to the vibratory needlebar frame 19 by mechanism comprising a rock lever 21 pivotally supported in a lug 22 (Fig. 1) preferably cast integral with the head 13. The lower end of the rocklever 21 is operatively connected to a horizontal extension 23 projecting from the lower end of the vibratory needle-bar frame 13, and the upper end of the rock-lever 21 is connected by a horizontal link 24 disposed externally at the rearward side of the bracket-arm 12. The other end of the link 24 (Fig. 5) is connected by a short link 25 to the lower end of an arm 26 depending from an oscillatory frame member 27 freely journaled on a fulcrum shaft 28 fixed in the opposite walls of the bracket-arm 12. To restrain the oscillatory frame member 27 against sidewise shift on the fulcrum shaft 28, the frame member 27 is slotted, as at 29 (Fig. 6), into which slot is fitted a stop-collar '30 secured to the fulcrum shaft 28 by the set-screw 3'1.

Projecting upwardly and laterally from .the oscillatory frame member 27 is a second arm 32 which extends through a cutout 33 formed in the front wall of the bracket-arm 12 so as to be located outside the confines of the sewing machine frame. As will be seen in Fig. 2, the free end of the arm 32 is formed with a split hole into which is inserted a cam-follower member indicated generally in the drawings by the reference character 34. Adjacent the split hole the arm 32 is formed with an extension providing a finger-piece 32'. The cam-follower 34 is biased into engagement with the periphery of a rotary pattern member or cam, indicated generally as P, soon to be described, by a coil-spring 35 anchored at 36 to the machine frame and at its other end connected by' a lever pin 37 (Fig. 5) to the oscillatory frame member 27.

From the foregoing, it will be understood that during the operation of the machine the oscillatory frame member 27 is spring biased downwardly so that the cam follower 34 engages the rotary pattern member and is thus caused to oscillate about the axis of the fulcrum shaft 28. Oscillation of the frame member 27 imparts lateral movements to the link 24 through the short link 25 and in order to translate these lateral movements into effective endwise reciprocatory movements the link 24 is fitted with a slide-block 38 which enters a slideway 39 formed in a guide-head 40. The guide-head 40 is carried by a shaft 41 (Fig. 6) which is journaled in a conventional type of control assembly supported in the bracket-arm 12 and fitted with a plurality of control levers 42 and 43 by which the angular position of the slideway can be regulated. With a set position of the guideway 39, the endwise reciprocatory movements of the link 24- are dependent upon the character of the pattern member P. Thus, the pattern member controls the stitch pattern produced by the laterally vibrating needle.

As is illustrated in Figs. 2, 6 and 7, the pattern member P is fixed on a cross-shaft 44 geared to be driven by the mainshaft 15 through gear 45 meshing with gear 46, the ratio between the gears 45 and 46 preferably being of a ratio of 18-to-1.

As previously mentioned, it is the purpose of the present invention to provide a pattern member such that the frequency of stitch-pattern duplication can be changed to exceed the ratio between the gears 45 and 46, that is to say that the frequency of stitch-pattern duplication can be made to occur only after the crossshaft 44 has made more than one complete revolution. To that end, a pattern member has been developed which can be readily applied to a machine constructed along the lines of the sewing machine forming the subject of the Perla Patent No. 2,756,703, previously referred to.

Referring to Figs. 1, 2 and 3, one form of pattern member comprises a unitary assembly including a casing or frame 47 U-shape in cross-section and housing a flexible belt 4-8 formed on its inner face with cleats 49 adapted to enter notches in the periphery of a driving sprocket 50 and an idler sprocket 51. The driving sprocket 50 is freely journaled on the reduced bearing extension 52 integral with the upper end of the frame 47, while the idler sprocket 51 is freely journaled on a shouldered stud 53 fixed on the lower end of the frame 47. The driving sprocket 50 is drilled at 54- to receive a dog-pin 55 projecting from a flange 56 integral with the cross-shaft 44 so that as the cross-shaft is rotated by the main-shaft of the sewing machine the driving sprocket 50 is turned to advance the pattern belt 48. The pattern belt is formed with a series of cam-lobes 57 on its periphery and as these cam-lobes pass beneath the cam-follower 34 the frame member 27 is oscillated about the fulcrum shaft 28 and, depending upon the angular position of the slideway 39, imparts endwise reciprocatory movements of varying magnitude to the link 24. These endwise reciprocatory movements of the link 24 eifect lateral vibration of the needle. It will be appreciated that the pattern member shown in Figs. 1, 2 and 3 is a unitary device and is readily attached to the sewing machine by placing the device upon the cross-shaft extension 58 with the dog-pin 55 in the dog-receiving hole 54 in the driving sprocket 50. A shouldered thumb-screw 59 is then tightened and this thumb-screw together with a spring-clip 60 and pin 61 retain the pattern member in operative position on the sewing machine.

Fig. 4 illustrates a slightly modified form of pattern member, difliering from that shown in Figs. 1, 2 and 3 in that a much smaller frame is provided and no idler sprocket is employed to assist in controlling the flexible pattern belt 48. In Fig. 4, the frame, indicated as 62,

houses only a portion of the driving sprocket 50 and functions more as a guard member or cover to maintain the flexible belt 48 in engagement with the driving sprocket 50. One of the advantages of having the frame 62 formed as illustrated in Fig. 4 is that a flexible belt of indeterminate length can be used, thus making it possible simply by changing to belts of different lengths to obtain any desirable frequency of stitch-pattern duplication required.

Figs. 6, 7 and 8 disclose another form of pattern device which also can readily be applied to an existing sewing machine of the type forming the subject of the above mentioned Perla Patent No. 2,756,703. This pattern device comprises a drum or, what is commonly called, a switch cam 63 adapted to be detachably clamped upon the cross-shaft extension 58 by means of a thumb-screw 64. The periphery of the switch cam 63 is formed with a raised endless cam-track 65 provided on its top surface with a series of cam-lobes 66. The arm 32 of the oscillatory frame member 27 is fitted with a cam-follower having a tubular body 67 (Fig. 7) fitted with a slider 68 formed with a depending followerpin 69 on which is mounted, for vertical movement, a cam-track embracing shoe 70 biased into engagement with the cam-track 65 by a coil spring '71. As the switch cam 63 is rotated by the cross-shaft 44 the shoe 70, being held in cam-track embracing position by the coilspring 71, causes the follower-pin 69 to stay in engagement with the top surface of the cam-track 65 and the cam-lobes 66 formed on that top surface effect a rising and falling of the frame member 27, which as previously described imparts vibratory movements to the needle bar of the sewing machine. It will be understood that with a switch cam made in accordance with the drawings, the cam will make three complete revolutions before the stitch pattern is repeated.

It will be understood that the stitch pattern defined by the contour of the flexible belt 48 or the cam-lobes 66 of the switch-cam 63 will be repeated only after the follower 34- or 67 has traversed the entire length of the belt or the cam-track 65 and that the follower having traversed the entire length of the pattern member has completed one cycle of action of the pattern member.

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

1. In a sewing machine, a frame including a work-supporting bed and a standard rising from said bed and terminating into a bracket-arm overhanging said bed, a laterally vibratory needle-bar frame mounted in said bracketarm, a needle-bar journaled for endwise reciprocatory movements in said needle-bar frame, a rotary shaft disposed longitudinally of and journaled in said bracketarm, a needle-bar frame vibrating connection member disposed lengthwise of said bracket-arm and having one end operatively connected to said needle-bar frame, a second shaft arranged transversely of said rotary shaft and journaled in said bracket-arm, a gear on said rotary shaft, a gear on said second shaft meshing with said gear on said rotary shaft, a pattern-member follower located adjacent the end-portion of said second shaft, means operatively connecting said pattern-member follower with said needle bar frame vibrating connection for transmitting motion of said pattern-member directly into lateral vibration of said needle bar, and a pattern attachment detachably mounted on the end-portion of said second shaft and arranged to be engaged by said patternmember follower, said pattern attachment comprising a body member having a plurality of stitch-pattern defining cam-lobes which collectively produce a single cycle of action of said body member, said body member being supported to turn about an axis coinciding with the axis of said second shaft, and means operatively connecting said body member to said second shaft so that the ratio of the number of revolutions of the rotary shaft to the number of stitch-pattern cycle duplications is difierent than the ratio of the gearing connecting said second shaft to said rotary shaft.

2. A mechanism as set forth in claim 1 in which said pattern attachment comprises a switch-cam.

3. A mechanism as set forth in claim 1 in which said pattern attachment comprises a drum, and in which said stitch pattern defining cam lobes comprise a raised endless cam-track formed on the periphery of said drum.

4. A mechanism as set forth in claim 1 in which said pattern attachment comprises a drum, in which said stitch pattern defining cam lobes comprise a raised endless cam track formed in spiral fashion on the periphery of said drum and in which the pattern-member follower comprises a tubular body arranged substantially parallel to the axis of said drum, a slider carried by said tubular body, a follower pin carried by said slider, a cam track embracing shoe mounted on said follower pin and disposed in engagement with said cam track, and a spring means acting to bias said shoe into yielding contact with said cam track.

5. In a sewing machine, a frame including a bracketarm terminating at its free end in a head, a laterally vibratory needle-bar frame mounted in said head, a needle-bar journaled for endwise reciprocatory movements in said needle-bar frame, a rotary shaft journaled in said bracket-arm, a needle-bar frame vibrating connection member having one end operatively connected to said needle-bar frame, a second shaft journaled in said frame and operatively connected to said rotary shaft, said second shaft having an exposed end, a pattern-member follower operatively associated with said needle-bar frame vibrating connection member, and a pattern member attachment detachably connected to the exposed end of said second shaft, said pattern member attachment comprising a flexible belt having a series of cam-lobes secured thereto and adapted to be engaged by said patternmember-follower, a belt driving sprocket, a casing on which said belt driving sprocket is freely journaled, means securing said casing on said frame with the cam-lobes on said belt in cooperative relation with said patternmember follower, means connecting said belt sprocket to said second shaft, and means on said casing for maintaining said belt in driving relation with said sprocket.

6. In a sewing machine, a frame including a bracketarm terminating at its free end in a head, a laterally vibratory needle-bar frame mounted in said head, a needlebar journaled for endwise reciprocatory movements in said needle-bar frame, a rotary shaft journaled in said bracket-arm, a needle-bar frame vibrating connection member having one end operatively connected to said needle-bar frame, a second shaft journaled in said frame and operatively connected to said rotary shaft, said second shaft having an exposed end, a pattern-member follower operatively associated with said needle-barframe vibrating connection member, and a pattern member attachment detachably connected to the exposed end of said second shaft, said pattern member attachment comprising a casing having a bearing extension apertured to be mounted on the exposed end of said second shaft, a belt driving sprocket freely journaled on said bearing extension, means connecting said sprocket to said second shaft, and a flexible belt engaging said sprocket and having a series of cam-lobes secured thereto and adapted to be engaged by said pattern-member follower.

7. In a sewing machine, a frame including a bracketarm terminating at its free end in a head, a laterally vibratory needle-bar frame mounted in said head, a needlebar journaled for endwise reciprocatory movements in said needle-bar frame, a rotary shaft journaled in said bracket-arm, a needle-bar frame vibrating connection member having one end operatively connected to said needle-bar frame, a second shaft journaled in said frame and operatively connected to said rotary shaft, said second shaft having an exposed end, a pattern-member follower operatively associated with said needle-bar frame vibrating connection member, and a pattern-member attachment detachably connected to the exposed end of said second shaft, said pattern-member attachment comprising a casing having a bearing extension apertured to be mounted on the exposed end of said second shaft, a first belt driving sprocket freely journaled on said bearing extension, means connecting said first sprocket to said second shaft so as to be driven thereby, an idler sprocket freely journaled on said casing and spaced from said first sprocket, and a flexible belt running on said sprockets and having a series of cam-lobes secured thereto and adapted to be engaged by said pattern-member follower.

8. In a sewing machine, a frame including a bracketarm terminating at its free end in a head, a laterally vibratory needle-bar frame mounted in said head, a needlebar journaled for endwise reciprocatory movements in said needle-bar frame, a rotary shaft journaled in said bracket-arm, a needle-bar frame vibrating connection member having one end operatively connected to said needle-bar frame, a second shaft journaled in said frame and operatively connected to said rotary shaft, a pattern-member follower, means operatively connecting said pattern-member follower with said needle-bar frame vibrating connection member for transmitting motion of said pattern-member follower directly into lateral vibration of said needle-bar frame, and a pattern device, means drivingly connecting said pattern device to said second shaft, said pattern device comprising a pattern-member consisting of a flexible belt having a series of cam-lobes secured thereto and adapted to be engaged by said pattern member follower, a belt driving sprocket, means connecting said belt sprocket to said second shaft, and meansfor maintaining said belt in driving relation with said sprocket.

References Cited in the file of this patent UNITED STATES PATENTS 303,317 Ostrom Aug. 12, 1884 1,551,453 Aromson et a1 Aug. 25, 1925 1,573,138 Brase Feb. 16, 1926 1,573,139 Brase Feb. 16, 1926 1,611,372 Rader Dec. 21, 1926 2,244,424 Mahany June 3, 1941 2,653,557 Casas-Robert et a1. Sept. 29, 1953 2,741,107 Garner et a1. Apr. 10, 1956

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