US2858782A - Needle vibration controlling mechanisms for zigzag sewing machines - Google Patents

Description

A. F'LDAMICO 2,858,782 NEEDLE VIBRATION CONTROLLING MECHANISMS FOR Nov. 4, 1958 ZIGZAG SEWING MACHINES 2 Sheets-Sheet 1 Filed May 26, 1954 INVENTOR. Anthony E Ohm c0 WITNESS I 777 ATTORNEY A. F. DAMICO 2,858,782 NEEDLE VIBRATION CONTROLLING MECHANISMS FOR w Nov. 4, 1958 ZIGZAG SEWING MACHINES 2 Sheets-Sheet 2 Filed May 26, 1954 INVENTOR.

Anthony I? Dldm/co ATTORNEY NEEDLE VIBRATION CONTROLLING MECHA- NISMS FOR ZIGZAG SEWING MACHINES Anthony F. DAmico, South Norwalk, Conn., assignor I to The Singer Manufacturing Company, Elizabeth,

N. 3., a corporation of New Jersey Application May 26, 1954, Serial N0.4s2,423

4 Claims. 7 (11. 112-158) This invention relates to improvements in zigzag stitch sewing machines of a laterally vibrating needle type and hasfor an object to provide such a machine with-a novel mechanism including a rotary pattern cam for producing the lateral needle vibrations.

Another object of the invention is to provide means whereby the needle may be properly positioned laterally of the normal direction of work feed independently of the rotary pattern cam so as to produce straight stitching in a predetermined path.

A further object of the invention is to provide means whereby the needle may be maintained in a predetermined operable position whenever the rotary pattern cam is removed from the machine.

With the above and other objects in view, the invention comprises the devices, combinations, and arrangements of parts hereinafter described in connection with the accompanying drawings which illustrate a preferred embodiment of the invention, from which the several features of the invention and the advantages attained thereby will be readily understood by those skilled in the art.

In the drawings:

. Fig. 1 represents a rear side elevation view of a sewing machine containing the presentimprovements and having its top and rear cover plates removed whereby the internal mechanism may be viewed.

Fig. 2 represents, on an enlarged scale, a-sectional view taken substantially along the line 2-2 of Fig. 1.

Fig. 3 represents, on an enlarged scale, a sectional view taken substantially along the line 3-3 of Fig. 1.

Fig. 4 represents, on anenlarged scale, ai-sectional view taken substantially along the line 4-4 of Fig. 1.

Fig. 5 represents a sectional View taken substantially along the line 5-5 of Fig. 4.

Fig. 6 is a fragmentary view of the front side of the sewing machine and particularly illustrating the pattern cam, the cam follower and a manual control means for altering the movements of the needle-bar as imparted thereto by the rotary cam.

Fig. 7 represents, on an enlarged scale, a sectional view taken substantially along the line 7-7 of Fig. 6.

. Referring-to the drawings, the sewing machine illustrated has a bed-plate 10 afiording a'work-support-from one end of which bed-plate rises a hollow standard 11 ofv a bracket-arm 12 overhanging the bed-plate and terminating at its-free end in a head .13; 3 The bracket-arm 12 is open at its upperportion as at 14 (see Fig. 2) and at its back side as at 15 (see Fig. 1), which openings are adapted to be closed by means of cover-plates, not herein shown, which may be removably secured in positions over the openings 14 and 15 by any conventional means. I 1

. R-otatably journaledin suitable bearings provided in the .bracketrarml 12 is a horizontally disposed main shaft 16 extending. lengthwiseof the bracket-arm andcarrying at itsone end a. driving pulley 17., -At its opposite end, the main shaft 16 is connected to drive a conventional "ice 2 type of needle thread take-up mechanism, not herein shown, as well as a needle-bar designated by the numeral 18.

The needle-bar 18 carries at its lower end a needle 19 and is journaled for endwise reciprocation in suitable bearings provided in a vibratory frame or gate 20. The frame 20 is pivotally hung in a conventional manner upon a screw stud 21 carried by the upper portion of the head 13 to provide for swinging movements of the frame 20 about a pivot axis substantially transverse to the axis of rotation of the main shaft 16. For more detailed.

views and explanations of the present type of vibratory needle-bar frame, reference may be had to U. S. Patent No. 2,297,197, of Bolter, dated September 29, 1942.

Cooperating with the needle 19 below the bed-plate 10 in'the formation of stitches is the usual loop-taker mechanism which is not herein illustrated and forms no part of the present invention. Also located beneath the bed-plate 10 but not herein illustratedv is the usual type of work-feeding mechanism.

Extending rearwardly from the lower end of the needle-bar frame 20 is an arm 22 to which a pitman 23 is pivotally secured by means of a pivot stud 24. The pitman 23 is disposed within and lengthwise of the hollow bracket-arm 12 so that its rear end portion may be connected with mechanism which actuates the pitman back and forth lengthwise of itself thereby to impart lateral Zigzag movements to the needle-bar frame 20 and its associated needle 19. This mechanism may also be adjusted so as to position the needle-bar frame in a fixed position thereby to permit the needle 19 to be reciprocated up and down in a fixed vertical path to produce straight stitching.

More specifically, the rear end of the pitman 23 is provided with a terminal portion 25 which is adapted to be connected by Way of mechanism, hereinafter described in detail, to a rotary pattern cam 26, of which the peripheral portion 27 may be tracked by a cam follower for the purpose of imparting a predetermined pattern of motion to the pitman 23 to the end that a predetermined pattern of ornamental stitching may be produced by the sewing machine.

The rotary pattern cam 26, as will hereinafter be described, may be removed from the machine to theend that other pattern cams may be substituted therefor so that the operator may produce various types of ornamental stitch patterns by merely changing the pattern cams. Also, as will hereinafter be described, the pattern,

cam 26 may be entirely removed from the machine and means are provided with the machine whereby it may be operated in a mannerof a conventional straight stitching machine.

Referring particularly to Figs. 1 and 2, the pattern cam 26 is provided with a central aperture 28 so that the cam may be mounted upon the distalgend portion of a shaft 29 which is suitably mounted in bearing bosses 30 and 31 formed within the bracket-arm 12. The distal end portion of the shaft 29 is provided with a cylindrical collar 32 against which the cam 26 may be placed and locked by means of a thumb nut 33. The thumb nut 33 may be tightened against the cam '26 due tothe fact that the outboard end of the shaft 29 is threaded. So as to time the cam 26 with the remaining portion of the sewing mechanism, the shaft hub 32-is provided with a pin 34 which is adaptedto engage an appropriate aperture 35 formed within the cam 26. .An intermediate portion of the rotary cam shaft 29 has fixed.

thereon a gear 36 which meshes with a worm gear 37 fixed upon the rotary main shaft 16. Thus, rotation of the main shaft 16 will, through the gears 36 and 37, rotate the cam 26 at a predetermined speed.

Referring particularly to Figs. 1, 2 and 6, there is mounted'withinand between the side walls of the bracket-arm 12 an oscillatory shaft 38 which is disposed in parallelism with the rotary cam shaft 29. The opposite end portions of the rock-shaft 38 extend through their associated side walls of the sewing machine bracketarm 12 and the forward end of the shaft 38 has fixed thereon, in a conventional manner, a bell-crank lever 39 (see Fig. 6) of which one arm 40 carries a laterally projecting follower element 41 which is normally biased into engagement against the periphery 27 of the cam 26 by means of a coil spring 42.

As may be best seen from Figs. 1 and 2, the spring 42 has its one end portion secured to a post 43 fixed Within the bearing boss 30, while the other end portion of the spring is connected with a post 44 carried by-a collar 45 fixed to the rock-shaft 38 in a conventional manner. The spring 42 will urge the rock-shaft 38 to turn in a direction" such that the cam follower 41 Will faithfully track the peripheral portion of the cam 26 to'the vendjthat the rock-shaft 38 will be oscillated back and forth in conformity with the pattern of the cam.

As may be observed from Fig.6, an arm 46 of the bell-crank lever 39 is disposed directly beneath a boss 47 provided on the forward side of the bracket-arm 12, which boss is disposed directly within the path of movement of the arm 46 which has threaded therein a screw 48 which may engage the boss 47 so as to function as an adjustable stop for arresting the downward movement of the arm 40 in the event that the cam 26 is removed from the machine. A nut 49 cooperates with the screw 48 so as to lock the latter in any desired position of adjustment. Also, as will hereinafter be set forth in more detail, the screw 48 may be employed for shifting the follower 41'out' of'engagement with the cam 26 while the latter is in its operative p osition.

The rear end portion of the rock-shaft 38 is provided with a radial crank 50 fixed'to-th'e shaft 38 by means of a set screw 51. The end portion of the crank 50 is pivotally connected with a link 52 by means of a conventional type of pivot screw 53. As may be seen from Figs. 1,2, 3 and 4, the lower end portion of the link 52 is pivotally connected with the terminal portion 25 of the pitman 23 by means of a connector pin 54. From the above, it will be understood that the rotation of the main shaft 16 will actuate the rotary pattern cam 26 through'the medium of the gears 36 and 37 to the end that the rock-shaft 38 will be oscillated back and forth through the medium of its cam follower 41. The rocking of the/ shaft 38 will, in turn, oscillate its crank 50 and, thus, through the link 52, impart rising and falling motions to the terminal portion 25 of the pitman 23. In order to translate the lateral vibratory movements of the pitman 23 into effective endwise reciprocatory movements, thereby to impart'swingin'g movements to the needle-bar frame 20, a guide block 55 is carried upon the inner end portion of the pin 54, which guide block is shiftably disposed within a guideway 56 constituted by a rearwardly open slot formed in the outer or rearwardly exposed face of a bodily adjustable guide member 57. The guide member 57 is rigidly locked by means of a shoulder screw 58 to a crank member 59 which is integrally formed upon the rear end portion of a'" hollow shaft 60 which is rockably supported within an aperture 61 formed within the bracket-arm 12.

More specifically, the guideway 56 is cylindrical in form and has slidingly received therein the guide member 55 which is also cylindrical in form and which is secured to the inner end portion of the pivot stud 54 by means of a screw member 62. From this, it will be apprecitaed that the rotary movements of the cam shaft 29'wi1l, through the link 52, actuate the guide 55 length- Wise of the guideway 56 so as to produce endwise movements in the pitman 23 in accordance with the angular adjustment of the guide member 57. Manifestly, whenever the guide member 57, together with its associated member 59, are disposed-in a manner such that their common longitudinal axis forms a ninety degree angle with the line connecting the centers of the pivot pins 24 and 54 of the pitman no substantial endwise movement will be imparted to the needle-bar gate 20 and, thus, the needle 1? will be permitted to reciprocate up and down in a fixed vertical path. However, by the same token, when the guide member 57 with its associated member 59 are adjusted about the longitudinal axis of their shaft 60, the needle-bar frame 20 will be moved back and forth lengthwise of the bed-plate 10 so as to produce zigzag stitches. From this, it will be appreciated that as the angle between the longitudinal axis of the guideway 56 becomes more acute relative to the line connecting the pitman pivot axes 24 and 25 the greater will be the amplitude of lateral movement imparted to the needle-bar frame 20.

From the above, it will be readily appreciated that with the operation of the present machine a rotary pattern cam 26 having a predetermined peripheral shape may be placed upon the machine in a manner as hereinabove described for producing a predetermined pattern of movement of the needle-bar frame 20. However, it will also be understood that as the guide member 57 is angularly adjusted about its pivot axis the pattern of movement imparted to the needle-bar frame 20 by the rotary pattern cam may be altered so as to increase or decrease the amplitude of lateral needle-bar vibration.

In order to facilitate the adjustment of the guide member 57, the hollow shaft 60 extends beyond the confines of the bracket-arm 12 and has mounted thereon a hand lever 63. As may be best seen from Figs. 2, 6 and 7, the hand lever 63 is provided with a finger piece 64 which facilitates the manual adjustment of the member 63. Also provided on the member 63 is a pointer element 65 which traverses across the face of the bracket-arm 12. For the purpose of indicating the amount of adjustment the bracket-arm may be provided with appropriate indicia numbers which are generally indicated by the'numeral 66. In order to lock the hand member 63 many position of adjustment, there is associated therewith a hand screw 67 which is threaded directly into the bracket-arm 12 and whose shank is disposed within an arcuate'slot 68 formed within the hand lever 63. By. tightening a thumb nut 67"against the lever 63, the latter may be locked in any selective position of adjustment.

As hereinabove pointed out, the bell-crank lever 39 with its cam" follower 41 is provided with an abutment arm 46 which, together with the boss member 47, function to arrest the downward movement of the'foll'ower arm 40 under the action of the coil spring 42 whenever the cam member 26 is removed from the machine. From this, it will be understood that with a proper adjustment of the screw 48 carried by the bell-crank lever 39, the arm 40 may be arrested in its downward movement in a position such that the needle-bar gate 20 may be maintained in an optimum position for producing straight line stitching upon the removal of the pattern cam 26. However,

as also hereinabove pointed out, straight stitching may be effected even with the rotary'pattern cam in place whenever the guide member 57 is adjusted so that its longitudinal axis will form a ninety degree angle with a line connecting the pitman pivot studs 24 and 54. However, since the axis of the guideway 56 is straight rather than curved, some small degree of endwise movement will beimparted to the needle 19 by the cam 26 even though the guideway is placed in its so-called no-movement position. Therefore, under some circumstances, the operator might desire to remove the cam 26 whenever straightaway stitching is to be effected by the machine.

The present invention also contemplates a second form of'adjusting means which will enable the operator mannally to position the needle-bar frame 20 upon the removal of the cam 26. Referring particularly to Figs. 3 to 7, there is rockably disposed'within the hollow shaft 60 a shaft 70 whose inner end carries eccentrically thereof a pin 71 which is disposed within a slot 72 formed within a plate 73 slidably mounted within a rectangular opening 74 formed between the ,elements'57 and59 of the guide member structure. The lower portion vof the. plate 73 carries a pin 75 which projects into the guideway 56. However, whenever the shaft 70 is adjusted so that its eccentric pin 71 is in its lowermost position, the pin 75 of the plate 73 is disposed below the guide 55 so as not to engage the guide during its normal cam-actuated endwise movements within the guideway 56. However, by shifting the shaft 70 about its longitudinal axis the pin 75 may be made to engage the lower portion of the guide element 55 thereby to elevate the latter element lengthwise of the guideway 56. From this, it will be appreciated that with this mechanism it is possible to raise the cam follower 41 to a position where it will no longer engage the cam 26 and this action will effectively arrest all lateral movements of the needle-bar frame 20 and its associated needle 19.

However, this adjusting mechanism is primarily adapted to be employed whenever the cam 26 is removed from the sewing machine. It is contemplated that upon the removal of the cam 26 the shaft 70 may be adjusted so as to place the needle 19 in any one of several selective positions of adjustment laterally of the Work-support 10, thereby to position the needle in its optimum position for straightaway stitching. In order to facilitate this adjustment of the shaft 60, its forward end portion carries a hand lever 76 fixed upon the reduced end portion 77 of the shaft 70 by means of a set screw 78. Referring particularly to Figs. 6 and 7, it will be appreciated that upon the turning of the hand lever 76 the pin 75 will be raised and lowered so as to shift the guide 55 up and down within the guideway 56 all of course under the influence of the coil spring 42. The hand lever 76 is placed in sliding arrangement with the first mentioned hand lever 63, and as may be best observed in Figs. 6 and 7, the face of the lever 63 is provided with three small apertures designated by the numerals 79, 80 and 81, which apertures or detents cooperate with a plunger 82 for the purpose of producing a tactual signal which indicates to the operator any one of three predetermined positions of the needle 19. More specifically, the plunger 82 is mounted within an aperture 83 formed within the hub portion of the hand lever 76, which aperture 83 has its one end adapted to be closed by a screw 84 which forms an abutment seat for a spring 85 which biases the plunger 81 towards the face of the hand lever 63. From this, it will be appreciated that as the operator turns the handle 76 relative to the hand lever 63 the plunger will be shifted over the face of the hand lever 63 and will find its way into any one of the three detent apertures 79, 80 or 81 thereby to advise the operator that the needle is positioned in its extreme left-hand, middle or right-hand positions relative to the length of the bed-plate. Therefore, the operator may place the needle in any of these positions and thereafter produce straightaway stitching whenever the cam 26 is removed from the machine. Naturally, all upward movements of the guide element 55 lengthwise of the guideway 56 are made in opposition to the spring 42 and, therefore, as the hand lever 76 is moved back and forth the guide element 55 will faithfully shift up and down lengthwise of the guide member 56 in response to the movements of the handle 76 and the action of the spring 42.

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

1. In an ornamental seam sewing machine having a hollow bracket-arm, a vibratory needle-bar frame carried by said bracket-arm, a needle-bar journaled for end- Wise reciprocation in said frame, a rotary pattern cam 7 removably mounted upon said machine, a c'am'follower element for engaging said cam, a pitrn'an connecting said follower element with said frame for imparting the mo-- tions of said pattern cam to said frame, a hollow shaft mounted within said bracket-arm for rocking movements about its longitudinal axis, a guideway fixed upon said hollow shaft for altering the, needle-frame vibrating movement produced by said pattern cam in response to movements of said hollow shaft, guide means carried by said pitman and traversing said guideway during the operation of said pattern cam, and manually operable means including a rotative shaft mounted within and lengthwise of said hollow. shaft for shifting said guide means relative to said guideway whenever the pattern cam is removed from the machine thereby to vary the position of said needle-bar frame.

2. In an ornamental seam sewing machine having a hollow bracket-arm, a vibratory needle-bar frame carried by said bracket-arm, a needle-bar journaled for endwise reciprocation in said frame, a rotary pattern cam journaled upon said machine, a cam follower for engaging said cam, spring means to bias said follower toward said cam, a hollow shaft mounted within said bracket-arm for rocking movements about its longitudinal axis, manually operable means for rocking said shaft about its axis, a guideway fixed at one end upon said hollow shaft, a pitman having a first end thereof connected with said frame for vibrating the latter ele, ment, guide means carried by a second end of said pitman and disposed within said guideway so as to be shifted lengthwise thereof, means connecting the second end of said pitman with said cam follower so as to shift said guide means lengthwise of said guideway, and manually operable means including a rotative shaft mounted within and lengthwise of said hollow shaft and an element disposed eccentrically of such rotative shaft and engageable with said guide means thereby to shift such guide means lengthwise of said guideway and against the action of said spring means.

3. In an ornamental seam sewing machine having a hollow bracket-arm, a vibratory needle-bar frame car-' ried by said bracket-arm, a needle-bar journaled for endwise reciprocation in said frame, a rotary pattern cam journaled upon said machine, a cam follower for engaging said cam, spring means biasing said follower toward said cam, connections between said'follower and said frame for imparting the motions of said pattern cam to said frame, a shaft journaled about its longitudinal axis and within said bracket-arm, with one end of .said shaft being connected with said cam follower and the other end being exposed at the front side of said bracket-arm, a handle connected with the exposed end of said shaft whereby said shaft may be turned thereby to shift said cam follower away from said cam and against the action of said spring, and means for releasably locking said handle in any one of a plurality of selective positions of adjustment.

4. In an ornamental seam sewing machine having a hollow bracket-arm, a vibratory needle-bar frame carried by said bracket-arm, a needle-bar journaled for endwise receiprocation in said frame, a rotary pattern cam journaled upon said machine, a cam follower for engaging said cam, spring means biasing said follower toward said cam, connections between said follower and said frame for imparting the motions of said pattern cam to said frame, said connections including an elongated guideway with a guide element slidingly mounted therein, a shaft journaled about its longitudinal axis and within said bracket-arm with one end of said shaft being connected with said cam follower through said guide element and the other end being exposed at the front side of said bracket-arm, 'a handle connected with the exposed end of said shaft whereby said shaft may be turned thereby to shift said cam follower away from 7 said cam andagainst the action of-said spring, and means 2,297,197 for;releesab1y locking saidhandle in any one of a plu- 2,669,204 rality of; selective tpositionsyof adjustment.

References Citedi n the file of this patent 5- UNITED;SIENIES PATENTS 7,213 9643641 1,551;4 S3 Arbn'son et a1. Aug. 25, 1925 8 Bolter-. Sept; 29, 1942;: Urscheleri t Feb.V16,. 1954" FOREIGNPATENTS Great Britain of 1908 Great Britain of 1909 France: Feb. 8, 1950

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