US2725839A - Ridge-forming mechanism throw-outs for blind-stitch sewing machines - Google Patents

Description

Dec. 6, 1955 PARRY 2,725,839.

RIDGE-FORMING MECHANISM THR -OUTS FOR BLIND-STITCH SEWING MAC NES Filed June 7, 1952 3 Sheets-Sheet 1 T HIH) .v o a AT TORNE Y Dec. 6. 1955 F. PARRY 2,725,339

RIDGE-FORMING MECHANISM THROW-OUTS FDR BLIND-STITCH SEWING MACHINES 3 Sheets-Sheet 2 Filed June 7. 1952 INVENTOR. $121414? ci arry ATTORNEY Dec. 6. 1955 F PARRY 2,725,839

RIDGE-FORMING ME ICHANISM THROW-OUTS FOR BLIND-STITCH SEWING MACHINES Filed June 7. 1952 3 Sheets-Sheet 3 IN V EN TOR. (fim (7 6m 3 WITNESS. BY

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ATTORNEY United States PatetitC "L, a corpora- This invention relates to blind-stitch sewing machines and it has for its "main objectto provide an improved automatic means for varying the field of action of the ridge-forming element to eifect the production of skipstitches and anchor-stitches.

Another object of the present invention is to provide a simplified manually actuated throw-out for the ridgeforming element regulating means, whereby the machine can be conveniently changed from a skip-stitch machine to a continuous anchor-stitch machine.

Another object of the invention is to provide a manually actuated throw-out device for the skip-stitch mechanism of a blind stitch machine, which device when located in one of its two positions of adjustment will render the skip-stitch mechanism effective to produce successive anchor stitches and skip stitches and when in its other position of adjustment will render the skip-stitch mechanism effective to lock the worktable of the machine in its normal elevated work-presenting position.

Still another object of the invention is to provide a ridge-forming element elevation-regulating means which is effective to permit a micrometer. adjustment of the normal working position of the ridge-forming element.

The foregoing and other objects and advantages, to 'gether With means wherebythe same may be carried into effect, will best be understood from the following description of a preferred embodiment thereof illustrated in the accompanying drawings, in which:

Fig. 1 is a top plan View of amachine constmcted in accordance with my invention, the bed cover-plate being removed andcertain of theparts being in section better to illustrate the details of the machine.

Fig. 2 represents a vertical sectional view taken longitudinally of the base and through the standard and the work-table, illustrating the mechanism for periodically tilting the work-table in order to form skip stitches and anchor stitches. c

Fig. 3 represents an enlarged horizontal sectional view taken substantiallyalong the line 3-3 of Fig. 2, showing the skip-stitch anchor-link and the manner in which the same is supported for adjustment into and out of skipstitch position. I

Fig. 4 represents an enlarged vertical sectional view through the free end of the machine-base, showing the linkage connecting the work-table elevating spring to the work-table. 7 1 V V c Fig. 5 represents an enlarged. vertical sectional view taken transverselyof the work-tablea jacent the stitching P t ti) l fite .t eit t piq th t d er o m merit tame presser-plate and the stitch-formingdevices;

Fig; represents a vertical sectional view taken substantially along the line 6 -6, Fig) 1, illustrating the mounting for the skip-stitch eccentric together with the belt drive therefor. A W I I I c Fig. 7 an enlai'ged front elevation of the skip-stitch h i llater, sh vi eix njfu l; l ne e p si on. f

the lever when the s kip stitch mechanism is'in operating nism with the or c skip-stitch mechanism imparts "a periodic tilting tion to the work-table, thereby to form skip stitches and anchor e 1' is i' ii si' t' i -l i,.l? tv' t e; link "shifted to a p siti'en h "no t ilti g imparted tofthe able and consequently only anchor stitchesare produce I Referring to the sewing'inacliiiie includes-a :"e c c c M bis'eiiii whavii a h 119w, taiidardll i ig from the "rear right hand earner therein Extend ng laterally. to; wa ds the left fr'oiii the upper ehdpf the standard is horizontal tipper -ari fi 12; and e5: iiaiiig forwardly the le'f't ha'n'd end thereof is a frame in '13, Atta to the free 'ei'iid ofthe' is statio ary ipresser-"p in feet in against which the wait is clamped by a v of conventional vertically yieldablje claiiiping 15ers 15 carried a wbrk table 16'wliich is supported by 'the'base-arni 10. Y N I Jeumaid in the hoiizo'ntal np ei arm 12 is 5 rota y shaft 17 which, through the 'iis'iial etihh'ei closed for 'exaiiiple in ihe U; s.- p" er'it sin curved needle 19 whit: I pres'ser-pl'a'te' i land iii apart; iia'i'isvei 7 dinal axisthefeofjthe forwaid caravan-penetratin i0 being from left to ii-gift p 'ting with the iiedle in the formatioii'of'chain stitches is a looper ZOi ac'tiia' d; in thefmanneitsliowii 'i n tiie Us. s i N0. 639,669,"Deliibi I9if1z899', The work i'sfed rearwaiiiiy' past the lie of a four-motion feed-dog :21 hole in the p'ressei-plate 14 cei've the. oppo'site' 'endsi'of a"horizontally disposed rodor shaft zs jourfialed iii which are integral-with abra by screws 33 to the base 10. r

The work tabl" 16 pr'ovides..suppo'r'tiiig 'nieans usual ridge forme'r 34 (FigLS) which fli operation with the presser-plate 1'4- to for" the material'- facilitating the penetration of tli bythecurved needle; 19 "so as 'tdfonii'bliii 7 wi'lllbe understood tli'aitthe niaterail isl bent oif as .it is fed over the ridge-former 34; and iii order to v minimize the friction imposeden the material b ridge-former during? 'this bending. 'a'c'tioh the" rid is o'scillated' in thezli'ne' of feed in a manner siich tha its forward movement is tiind' to" coiiiei'de with h' eerie" advance movement of thefedai'og" 21. As 'w'ill be in; F s: -1, 2 nd 5 xthe' ridge-former .34' is pref clamped iponthel'outeri nd of-a ifidge forriir' carrym shaft 35 journaled-inthe wdr tabl i6 'aii'd' t upstanding lags-3'0 a c 'ket 32 detac ii'ably secured tion' cured to its inner end a rock-arm 36. The rock-arm 36 is connected by a link 37 to the upper end of an upstanding rock-lever 38 secured on the exposed end of a pivotshaft 39 journaled in one of the side walls of the base 10. Preferably clamped to the inner end of the pivotshaft 39 is a downwardly extending rock-lever 40 connectedby a pitman 41 to an eccentric 42 mounted on the main-shaft 17. Rotation of the main-shaft 17 will impart to the ridge-former 34 oscillations about the axis of the ridge-former carrying shaft in timed relation with the stitch-formingand work-feeding mechanisms.

As previously described, the work-table 16 is supported on the pivot-shaft 25 and is spring-biased, by means later to be described, into an elevated working position. This working position in the present machine is obtained by means of a novel manually controlled work-table height adjusting device located in the work-table and controlled by a thumb disk located at the right hand end of the work-table. The work-table height adjusting device is best shown in Figs. 1 and 2 and comprises a rotatable eccentric or cam-shaped stop 43 mounted. on the lower end of a vertically disposed shaft 44 journaled adjacent its lower end ina bushing 45 pressed into a lug 46 integral with the work-table 16 and at its upper end in a bearing 47 provided in the work-table 16. The shaft 44 carries a worm-wheel 48 adjacent its upper end, and a spacing sleeve 49 maintains the shaft 44 in its proper elevated position in its bearings. Meshing with the wormwheel 48 is a worm 50 carried on a hand operated shaft 51 which is journaled in the work-table and carries at its free end a thumb disk 52; the shaft 51 being constrained against endwise movement by the reduced end of a set screw 53 which enters an annular groove 54 in the shaft 51. Cooperating with the eccentric or cam stop 43 is an abutment element or plunger 55 which is adapted to be constrained against endwise movement, in which case the machine produces successive anchor stitches, or be reciprocated endwise for a limited extent, in which case the work-table is periodically raised and lowered and the machine produces skip stitches and anchor stitches. Assuming that the machine is adjusted so that the plunger 55 is constrained against endwise movement, then it will be understood that manual turning of the thumb-disk 52'will effect a turning of the eccentric stop 43 and, depending on the direction of movement of the eccentricstop, the work-table will be elevated or lowered relative to the free end of the frame arm 13. It will be apparent that because of the large ratio between the worm and worm-wheel '48 and the small rise or eccentricity on the eccentric stop 43, a very accurate adjustment of the position of the work-table can be obtained. This is especially advantageous when blind-stitching very thin fabrics.

As mentioned above, ,means are provided for either constraining the abutment plunger against endwise movement or reciprocating the same in timed relation with the stitch-forming mechanism to produce successive anchor stitches and skip stitches. This skip-stitch means comprises a single mechanism equipped with a throw-out which can be operated whether or notthe machine is running. As will be seen in Fig. 2, the plunger 55 is mounted to reciprocate in the end wall of the base 10, and at-its inner end the plunger is fitted with a wrist-pin 56 mounted to turn in the spaced limbs of a yoke 56' formed on the forward end of a pitman-connector 57 whose other end is forked, as at 58, to embrace a slideblock 59 freely journaled on a skip-stitch rotary actuator or eccentric 60. The skip-stitch eccentric 60 (Fig; 6) is preferably formed integral with a belt-sprocket 61 which is freely journaled on a pivot-spindle 62 supported in bearings bushings 63 provided in the side-walls of the standard 11; the pivot-spindle 62 being constrained against endwise movement in its supporting bushings 63 by the stop-screws 64 threaded into the bushings. The slide-block 59 and the forked end of the pitrn n I lowered position.

. 4 i nector 57 are maintained in cooperative relation on the eccentric 60 by a flanged collar 65 which is secured on the pivot-spindle 62. The belt-sprocket 61 is driven preferably by a clip-belt 66 from a smaller belt-sprocket 67 fast on the main-shaft 17; the ratio between the beltsprockets 61 and 67 being of the order 2-to-l so that when the skip-stich mechanism is in operative position alternate anchor stitches and skip stitches are produced. Obviously, the ratio between the belt-sprockets can be of the order of 3-to-l or 4-to-1, in which case a plurality of skip stitches are made between the anchor stitches. Also, it will be appreciated that gearing may be used, instead of belting, to drive the skip-stitch eccentric from the main-shaft 17 Spring means is provided for maintaining the worktable 16 in its elevated working position determined by the selected position of adjustment of the eccentric stop 43. As shown in Figs. 1, 2 and 4, the pitman-connector 57 is formed with an offset rear end 68 into which is threaded a spring-tension-regulating screw 69 carrying a spring-connector 70 having a cross-bar 71 to which is hooked one end of a work-table elevating coil-spring 72. At its other end, the coil-spring 72 is secured to the inner end of a slide-rod 73 (Fig. 4) supported in the end-wall of the base 10 and connected at its outer end by a short link 73' to one side face of a pivotally mounted rockmernber 74. Connected to the other side face of the rockmember 74- is a link 75 connected to the depending front limb of the work-table 16. The linkage, including the slide'rod 73, rock-member 74 and link 75, provides means such that when the work-table is lowered by manual actuation of the usual knee-shift, the effort required by the operator becomes less as the work-table approaches its This particular feature is.t'ully described and claimed in another of my U. S. patent applications Serial No. 292,264, filed herewith and reference may be had to that application for a more complete description of the same. From the above description, it will be appreciated that the work-table elevation controlling eccentric stop 43 is yieldingly held in contact with the abutment plunger 55 by the coil-spring 72 which acts between the pitrnan-connector 68 and the work-table 16. It will be further understood that since the coil-spring 72 does act between the pitman-connector 68 and the work-table 16, and not between the base 10 and the work-table 16 as is customary in prior blindstitch machines, the pressure developed by the coilspring 72 is not transmitted to the skip-stitch eccentric 60, which additional pressure would increase the friction between the slide-block 59 and the fork 58 and increase wear, but is absorbed within the skip-stitch mechanism. The manner in which the coil-spring is mounted to eliminate the pressure exerted bythe spring from being transmitted back to the skip-stitch driving mechanism eccentric 60 forms the subject of another one of my U. S. patent applications Serial No. 292,261, now Patent No. 2,681,- 629, dated June 22, 1954, filed herewith and reference may be had to that application for a more complete disclosure of this feature.

In order to render the skip-stitch mechanism effective or ineffective to tilt the work-table 16 about its pivotal support 25, a manually actuated linkage is provided which controls the movement of the pitrnan connector 57 such that it imparts a slight endwise reciprocation to the abutment plunger 55 or holds the same stationary. The control linkage is arranged between the pitrnan connector 57 and the base 10 and comprises an anchor-link 76 (Fig. 3) secured at its upper end to an adjusting shaft 77 journaled through the machine-base 10 and confined against endwise displacement relative to the base 10 by the hub of the anchor-link 76 and a collar 78 mounted on the adjusting shaft. Pivotally connected to the other end of the anchor-link 76, by a fulcrum-stud 79, is one end of a control-link 80 formed at its other end with a lateral bearing projection 81 on which is journaled the pitman-connector 57;: the bearing projection 81 and control link 80 being formed with aelearance' bore 82 through which extends the adjusting shaft 77. Thead justing shaft 77 has 'securedonit, exteriorly of the base 10, a hand-lever'83 which is provided with a spring-biased .ball-detent 84 cooperating withtwo detent depressions 85 formed ina plate '86 attached to the side wall of the base the two depressions 85 defining an upper and a lower position. of the fulcrum-stud connection 79 between the anchor-lin'k 76 and the control-link '80. In the lower position of the fuicrum-stud 79, see Fig. 10, the control-link 80 is arranged so that its longitudinal axis is disposed substantially parallel with aline between the wrist-pin 56 and the axis of the skip-stitch pivot-spindle 62, in which lower position the control-link 80 swings an equal distance on opposite sides of the line between the wrist-pin 56 and the axis of the pivot-spindle 62 and does not force the pitmanv connector 57 to move endwise and impart any reciprocation to the abutment plunger 55. In fact, in the lower position of the fulcrum-stud 56, the abutment plunger 55 remains substantially stationary and thereby prtwides, in effect, a stationary stop which determine's an elevated position of the work-table- 16, in which elevated position consecutiveanchor-st-itch'es are formed.

When the hand-lever 83 shifted to the full 'line position as shown in Fig.7, the fulcrum st-ud' 79 is moved to its upper position as is shown in Fig. 91 When so shifted, the control link 80 assumes arr inclined position with: respect to the line between: the wrist-pin 56 and the axis of the skip-stitch. pivot-spindle 621- this inclined position, the: controhlinkiit) interferes with the free angu lar movement of thelpitman connectorST about the wrist pin 56- and induces,fint I motion to the vpitm'an; connector which is transmitted to the abutment-plunger 55; resulting in aperiodic lowering of the work-table 16: so that: alternate anchor'and skipstitchesare formed.

From the foregoing, it will be understood that-I have provided at throw-outforf the ridge-forming mechanism of ablind=stitch sewing machine, which: -thr'ow out can be actuatedat will: for converting: the machine from a skipstitch: machine to a continuous anchor-stitch machine; Also, itz'will' be appreciated thafi the throw-out is designedisot that,.in movingithe hand lever 83 from alien irate anchor and skip-stitch? position to continuous-anchor stitcht position, it is: unnecessary to manually adjust any stops or the like; the throw-out mechanism automatically lockingthe abutment-plunger 55* in: a: stationary position determining the normal elevated working posit-ion' of the worlotabie and consequently the ridge=former 34'.

Having thus set forth the nature of the invention; whattI claimherein isz- 1. hr a blind-stitch: sewing machine, the combination with a main name-including an overhanging arm; of a stationary pressenplate: attached to the free" end of said arm and provided: withan opening; stitch-forming mechanism mounted on said arm: and inclilding a" needle disposed for movement across said opening, a work-table mounted on= said main frame and having a portion underlying the'free'end' of said'overhjan'gingl arm, a ridgeforming element located below. said presser-plate fon projectinga ridge of fabric upwardly through said opening into needie penetrating position, skip-stitch connections for at intervals moving said ridge-forming element relative to said overhanging arm to form anchor stitches and skip stitches, and a control linkage for constraining the motion of said skip-stitch connections, means for maintaining said control linkage in operative relation continuously with said skip-stitch connections, and manually operable means carried by said control linkage for shifting said linkage into a first position of adjustment in which said skip-stitch connections are eifective to move said ridge-forming element toward and away from said overhanging arm and a second position of adjustment in addition; a slight reciprocat'ory I which said skip-stitch "connections are rendered efiecnfve to maintain said ridge-forming element in a normally elevated position relative to said overhanging'arm.

2. In a blind-stitch sewing machine, the combination with a main frame including an overhanging arm, of a stationary resser-plate attached to the free end of said arm and provided with an opening, stitch-forming mechanism mounted on said arm and including a needle disposed for movement across said opening, a work-table having a portion underlying the free end of said overhanging arm and mounted on said main frame for movement to"- ward and away from said overhanging arm, a ridge-form;- ing element supported by said work-table and located below said presser-plate for projecting a ridge of fabric upwardly through said opening into needle-penetrating position, skip-stitch connections for at intervals moving said work-table relative to said overhanging arm to form anchor stitches and skip stitches, a control linkage for constraining the motion of said skip-stitch connections, means for maintaining said control linkage in operative relation continuously with said skip-stitch connections, and manually operable means carried by said control linkage for shifting said linkageinto a first position of adjustment in which said skip-stitch connections died a movement of said work-table toward and away from said overhanging arm and a second position of adjustment in which said skip-stitch connections are rendered eifective to maintain said workt'able in a fixed position relative to said overhanging arm.

3. In a blind-stitch sewing machine, the combination with a mainframe including an overhanging arm, of a stationary presser-plate attached to the free end of said arm and provided with an opening, stitch-forming mechanism mounted on said arm and including a needle disposed for movement across said opening, awork-table having a portion underlying the free end of said overhanging armand mounted on said main framefor movem'ent toward and away from said overhangingam;- a ridge-forming; element supported by said work-table and located belowsaid presser-plate for projecting a ridge of fabric upwardly through said opening into needle pen'e: trating position; skip-stitch connections in'cluding a movablfiitlblifilieflt' elementfor' at intervals moving said worktablerelative to said overhanging arm to form anchor stitches and skipstitches, and'a control linkageassociated withsaid skip-stitch co'nections and having a firsf position of adjustment in which movement is imparted through said abutment element to move said work-table toward and away from said overhanging arm and a=-sec'- ond= position of adjustment in" which said abutment element is held stationary and acts asa stop to'maintain said work-table in a fixed normally elevated position relative to'said-overhangingarm.

4-. In a blind stitch sewing machine, the" combination with amain frame including an overhangingarm,- of a stationary presser -p'late attached to the' free end of said arm and provided with an opening, stitch-formingme'cha nis'm-mounted on said arm and including a needle dis posedfor movement across said opening, awork-table having a portion underlying the free end of said over: hanging arm and mounted onsaid main fra'm'e for movementtoward and away from said overhanging arm, a ridge-forming: element supported by said work table and located below said Presser-plate for'projecting ridge of fabric upwardly through said opening lawman-pane: trating position, skip-stitch connections for at intervals moving said work-table relative to said overhanging arm to form anchor stitches and skip stitches, said skip-stitch connections including a rotary actuator, a movable abutment element supported by said main frame, and a pitman-connector connected at one end to said abutment element and at its other end to said rotary actuator, and a control linkage operatively connected to said pitmanconnector and having one position of adjustment in which said pitman-connector is constrained to move said abutment element and a second position of adjustment in which said pitman-connector is caused to turn about its connection with said abutment member without imparting any movement to said abutment member.

5. In a blind-stitch sewing machine, the combination with a main frame including an overhanging arm, of a stationary presser-plate attached to the free end of said arm and provided with an opening, stitch-forming mechanism mounted on said arm and including a needle disposed for movement across said opening, a work-table mounted on said main frame and having a portion underlying the free end of said overhanging arm, a ridge-forming element located below said resser-plate for projecting a ridge of fabric upwardly through said opening into needle penetrating position, skip-stitch connections for at intervals moving said ridge-forming element relative to said overhanging arm to form anchor stitches and skip stitches, said skip-stitch connections including a rotary actuator, a reciprocatory abutment element journaled in said main frame, and a pitman-connector pivotally connected at one 'end to said abutment element and actuated at its other end by said rotary actuator, and a throw-out control linkage poeratively connected to said pitmanconnector, said control linkage including a control-link pivotally connected to said pitman-connector, an anchorlink pivotally connected to said control-link, and means for swinging said anchor-link into and out of a position in which the point of connection of the control-link with the anchor-link lies substantially in a straight line connecting the axis of rotation of the rotary actuator with the point of pivotal connection of the pitman-connector with the abutment element.

6. In a blind-stitch sewing machine, the combination with a main frame including an overhanging arm, of a stationary presser-plate attached to the free end of said arm and provided with an opening, stitch-forming mechanism mounted on said arm and including a needle disposed for movement across said opening, a work-table mounted on said main frame and having a portion underlying the firee end of said overhanging arm, a ridge-forming element located below said resser-plate for projecting a ridge of fabric upwardly through said opening into needle penetrating position, skip-stitch connections for at intervals moving said ridge-forming element relative to said overhanging arm to form anchor stitches and skip stitches, said skip-stitch connections including a rotary eccentric, a reciprocatory abutment element journaled in said main frame, and a pitman-connector pivotally connected at one end to said abutment element and actuated at its other end by said rotary eccentric, and a manually actuated throw-out control linkage operatively connected to said pitman-connector, said control linkage including a control-link having a bearing projection on which said pitman-connector is journaled, said bearing projection being bored to provide a clearance hole, an anchor-link pivotally connected to said control-link, an anchor-link adjusting shaft journaled in said main frame and extending through the clearance hole in the bearing projection of said control-link, and means secured on said anchorlink adjusting shaft for retaining said anchor-link in a selected one of two positions.

7. In a blind-stitch sewing machine, the combination with a machine frame, a presser-plate upon said frame, stitch-forming mechanism disposed above said presserplate and including a thread carrying needle, and a worktable movably mounted upon said frame in operative relation with said resser-plate, of an adjustable stop means carried by said work-table and operable to determine the normal operating position of said work-table relative to said resser-plate, said adjustable stop means including a stop-cam disposed to engage said machine frame, a shaft journaled in said work-table and carrying said stop-cam, a manually turnable member mounted on said work-table, and a worm and worm-wheel connection between said manually turnable member and said shaft.

8. In a blind-stitch sewing machine, the combination with a machine frame, a resser-plate upon said frame, stitch forming mechanism disposed above said presserplate and including a thread carrying needle, anda worktable movably mounted upon said frame in operative relation with said presser-plate, of an adjustable stop means carried by said work-table and operable to determine the normal operating position of said work-table relative to said presser-plate, said adjustable stop means including a stop-cam disposed to engage said machine frame, a first shaft journaled in said work-table and carrying said stopcam, a second shaft also journaled in said work-table and arranged transversely of said first shaft, gearing interconnecting said first and second shafts, and a thumb-disk secured on said second shaft and disposed for convenient manipulation by the operator.

9. In a blind-stitch sewing machine, the combination with a main frame including an overhanging arm, of a stationary presser-plate attached to the free end of said arm and provided with an opening, stitch-forming mechanism mounted on said arm and including a needle disposed for movement across said opening, a work-table mounted on said main frame and having a portion underlying the free end of said overhanging arm, a ridge-forming element located below said resser-plate for projecting a ridge of fabric upwardly through said opening into needle penetrating position, skip-stitch connections for at intervals moving said ridge-forming element relative to said overhanging arm to form anchor-stitches and skipstitches, said skip-stitch connections including an oscillatory member, a pivot pin joining said oscillatory member to said skip-stitch connections, and a control linkage associated with said skip-stitch connections to define a pivotal axis with respect to said main frame for movement of said oscillatory member, said control linkage having a first position of adjustment in which said pivotal axis with respect to said main frame is defined remote from the axis of said pivot pin joining said-oscillatory member to said skip-stitch connections whereby said skipstitch connections are effective to move said ridge-forming element toward and away from said overhanging arm, and a second position of adjustment in which the pivotal axis with respect to said main frame is defined substantially coincident with the axis of said pivot pin joining said oscillatory member to said skip-stitch connections whereby said skip-stitch connections are rendered effective to maintain said ridge-forming element in a normally elevated position relative to said overhanging arm.

References Cited in the file of this patent UNITED STATES PATENTS Moulton et al. May 16, 1939 Buono July 11, 1950

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