US2497746A - Presser device for sewing machines - Google Patents

Description

Feb. 14, 1950 TAMBURRO 2,497,746

PRESSER DEVICE FOR SEWING MACHINES Filed Dec 15, 1946 2 Sheets-Sheet 2 ATTORNE'K) Patenteci F al. 14, 1950 PRE'SSER DEVICE FOR SEWING MACHINES Francis P. Tamburro, Ozone Park, N. Y., assignor to Willcox & Gibbs Sewing Machine Company, New York, N. Y., a corporation of New York ApplicationDecember 13, 1946, Serial No. 716,161

17 Claims.

This invention relates to presser devices for sewing machines, and more particularly to devices of this type having pairs of artculated presser feet.

An object of the invention is to provide an improved artculated-foot type of presser device in which the relative positions of the presser feet when raised from the work may be controlled so as to suit various werk requirements.

Another object of the invention is to provide an improved articulated-foot type of presser device in which the relative pressures of the presser eet and positions of the latter when engaging a workpiece may be readily adjusted and controlled to adapt the presser device to various types of work, speeds of sewng, etc., and also to provide such a device in which the retracting or iifting movements of the presser feet in surmounting a cross seam or other obstruction are not adversely aiiected or impaired.

A further object of the invention is to provide en mproved presser device as above in which the control of the presser feet, either when rased or lowered and engaging a workpiece, is governed by a single, smple adjustment.

A stiil further object of the invention is to provide an improved presser device as above in which the controlling is automatically accomplished during use of the machine without requiring extra operations on the part of the operator.

A feature of the invention is the provision of a presser device as above which is extremeiy simple in constructon and economcal to manufacture.

In accomplishing the above objects, according to the invention, a presser device is provided comprising a front presser foot and a rear presser foot which are pivotally connected together by rocker arms, the letter being pivotally mounted on the lower end of a spring-urged presser bar carried by the sewng head of the machine.

Each presser foot may thus have independent pivotal movement on the rocker arms, and by vrtue of the latter being themselves pivoted, may have up and down movement which is virtually translational in nature.

The raising and lowering of the presser bar is effected by a liiter which has a laterally extending arm adapted to engage the lower end of the bar. Between the said lateraliy extending arm and the rear presser fout of the presser device a compression coii spring is mounted, and by this organization pressure in excess of that supplied by the presser bar is transmitted to the said rear oot.

A novel and simple adjustable mechanism is provided by whch, through connection with the frame of the machine,the relative pressures of the presser feet on a workpiece may be controlied and changed as well as the relatve positions of the presser feet. This novel mechanism also functions to control the relative positions of the feet when the letter are in lifted positon, disengaged from a workpiece.

In the embodiment of the invention illustrated herein this mechanism comprises a simpletilt lever which is pivotally carried on an eccentric stud or pivot mounted on the lower end of the presser bar. One end of the lever engages one of the rocker arms whch carry the presser feet, the point of engagement being adj aoent the pivot for the front presser foot, and the other end of the lever is adapted to engage a second arm which is provided on the lifter device for the presser bar.

The eccentric pivot and the tilt lever carried thereby are so arranged that when the 1ifter is holdin the presser bar in elevated position, the tilt lever may be engaged by the second arm of the lifter, and by adjustng the eccentric pivot the lever may be made to change the positons of the rocker arms, and therefore the relative positions of the presser feet. The range of adjustment of the tilt lever and eccentric pivot is such that the front presser foot may be maintaned in a poston considerably below the rear presser foot and vice versa, or the presser eet may be maintained in varicus adjusted postions inbetween these extremes, inciuding the position where both are on the same level.

Also, when the lifter is operated so that the presser bar is dropped to cause the presser feet to engage a workpiece, the arrangement of the tilt lever and eccentric pivot is such that the relatve pressures of the presser feet may be vared, as well as the relatve positions of these, and thus the presser device may be adjusted te best suit a particular type of work or a particular speed of feed, etc.

By makng the tilt lever cooperable with the lifter, the control of the pressures and positions of the presser feet is automatically accomplished by the actuaton of the lifter, and therefore the operator is relieved trom going through an additional operation in order to make eiectve the control of the presser feet.

The aotion of the tilt lever is such that the retracting or lifting movements of the presser feet in surmountng a cross seam or other 0b struction in the work may take place in the normal manner, and in tact may be facilitated by proper adjustment of the tilt lever, since such adjustment may relieve the front presser foot of some of its pressure, if this is found desirable.

By the provision of the tilt lever and the eccentrio pivot therefor, a single adjustment, eiected by turning the pivot one way or the other, is all that is necessary to obtain the desired control 3 of the presser feet when in both the raised and lowered positons.

The control of the presser feet is thus accomplished by few parts, namely, the eceentric pvot, the tilt lever and the actuating arm on the lifter which is cooperable with the tilt lever, and these parts are simple in construction and economical to fabricate and to install.

Other features and advantages will hereinafter appear.

In the accompanying drawings:

Figure 1 is a side elevaton, enlarged, of the improved presser device of the invention, a part only of the lifter mechanism being shown, and the throat plate of the sewing machine being shown in section. Thepresser device is being maintained in raised position by the lifter, and the adjustment of the device is such that both the front and rear presser feet are on the same level.

Fig. 2 is a view like Fig. 1 but with the adjustment altered so that the front presser foot is raised hgher than the rear presser foot.

Fig. 3 is a view like Figs. 1 and 2 but with the adjustment such that the front presser foot is lower than the rear presser foot.

Fig. 4 is a side elevation of the presser device in lowered position wherein the presser feet aan engage a workpiece, the adjustment of the device corresponding to the adjustment of Fig. 1.

Fig. 5 is a view like Fig. 4 but with the adjustment of the device corresponding to the adjustment of Fig. 2.

Fig. 6 is a front elevation of the presser device as shown in Fig. 5, the eccentric pivot and the tilt lever carried thereby being shown in section, and

Fig. 7 is a view like Figs. 4 and 5 but with the adjustment of the device corresponding to the adjustment of Fig. 3.

As shown, the presser device of this invention comprises a presser bar l carrying at its lower end a bracket II havng a split collar 12 and, secured to the latter, a yoke portion I3 from which a pair of arms I4 depend. 'Ihe arms I4 pivotally carry rocker levers or arms l which at their front ends pivotally mount a front presser foot I6 and at their rear ends a rear presser foot I'|.

By this construction the front and rear presser eet are individually pivotally movable on the rocker arms I5, and the front oot H3 may be raised and the rear foot l| lowered or vice versa by pivotal movement of the rocker arms en the depending arms I4.

Tlie presser device is associated with a machine having the usual frame F,. throat plate T, eed dogs D and needle NFig. 1.

For the purpose of raising and lowering the presser bar IU and the presser feet I6 and 11 carried thereby a lifter is provided in the form of a collar I8 carried on a shaft I9 which latter is secured to the machine frame (not shown), the collar being actuated by a driving arm 20 and having a lateral extension 2l carrying a flat arm 22 (see Fig. 4, broken lines) the remote end 23 of which extends under the bracket H for engagement with the underside thereof. Between the arm 23 and the rear presser foot H a compression coi1 spring 24 is mounted, one end of thespring encompassing a depending pin 25 secured to the arm end 23, and the other end of the spring being received in a recess 26 in the rear presser foot I1.

It will be seen that when the driving arm 20 of the lifter is forced downward, the arm 22 thereof will be raised and, after engaging the un- 4 dersurface of the bracket I I will raise the latter and the presser bar lil, together with the presser feet carried thereby, and will maintain this assemblage in raised position as shown in Figs. 1 through 3. When the driving arm 28 of the lifter is raised to releasing position, the spring pressure which is normally exerted on the presser bar I0, as is conventional in sewing machines, will force the presser bar and bracket ll, and the presser foot assemblage carried thereby down into work-engaging position, as shown in Figs. 4 through 7.

According to this structure the compression" spring 24 augments the pressure applied to the rear presser fooi; 11 by the rocker arms I5. The pressure exerted by the presser bar l0 is divided substantially equally between the presser feet [6 and I! when the letter are engaging a workpiece; however, because of the spring 24 the pressure of the rear presser foot I'| on the workpiece is ncreased beyond this by the amount of the spring pressure.

According to the present invention a nevel and simple mechanism is provided for controlling the relative positions of the presser eet [6 and I! when the letter are in their elevated positions as shown in Figs. 1 through 3, and for controlling the relative pressures which the presser eet exert on a workpiece, and the relative positions of the said feet when the latter are in their lowered positions as shown in Figs. 4 through 7.

This mechanism, in the embodiment of the invention illustrated herein, comprises a tilt lever 21 which is carried on an eccentric collar 28, the latter being secured by a screw 29 to one of the depending arms 14 of the bracket II. The foremost end of the tilt lever 21 is bent laterally at right angles to form a flange 30, the underedge of which is adapted to engage the upper surface 31 of the adjacent rocker arm l 5. The other end of the tilt lever 21 is somewhat hookshaped and has a bill 32 which is adapted to be engaged by a laterally extending arm 33 projecting from the collar is of the lifter.

Referring to Figs. 1 through 3, the parts are so organized and shaped that when the lifter is maintaining the presser bar In and the presser fooi: assemblage carried thereby in raised position, adjustment of the eccentric collar 28 will cause the foremost end of the tilt lever 21 to shift the rocker arms |5 against the expanding action of the compression spring 24, the hooklike end of the tilt lever being backed up and prevented from moving by the lifter arm 33. For example, when the eccentric collar or pivot 28 is in its lowermost position as shown in Fig. 3, the foremost end of the tilt leve'r 21 will depress the said ends of the rocker arms I5 to a considerable ex tent, thereby lowering the front presser foot [5 and raising the rear presser fooi: [1, the latter compressing the spring 24. When the eccentric collar 28 is in its uppermost adjusted position as shown in Fig. 2 the foremost end of the tilt lever 21 will allow the front ends of the rocker arms I5 to be raised under the expanding aetion of the spring 24, thereby enabling the letter to maintain the front presser foot [6 in a higher position than the rear presser font l'l. An intermediate adjustment of the eccentric collar 28, as shown in Fig. 1, causes the presser feet 16 and [1 to be maintained at the same level.

These difierent raised, relative positions of the presser feet 16 and I 1 are of advantage when handling dierent types and sizes of werk material's.

The tilt lever 21 and eccentric collar 28 also operate to control the relative pressures exerted by the front and rear presser feet on a workpiece, and to control the relative positions of these feet when in operative position as shown in Figs. 4 through '7. For example, when the eccentric collar 28 is adjusted in its lowermost position as shown in Figs. 3 and '1, and as the lifter is actuated to drop the presser bar and presser feet, the end 32 of the tilt lever will remain in engagement with the lifter arm 33 and will cause the lever to limit the position of the rocker arms I5 so that the rear presser foot 11 is maintained raised above the front presser foot I6. In such circumstance, the rear presser foot l1 does not engage the work, the sole engagement being effected by the front presser foot. By changing the adjustment of the eccentric collar 28 the rear presser foot may be lowerecl with respect to the front presser foot from the position shown in Fig. '1, and may be caused to engage a workpiece with varying amounts of pressure.

The adjusted positions of the eceentric collar 28 as shown in Figs. 1, 2, 4 and 5, are such that when the presser feet are lowered and in engagement with a workpiece, they exert their normal pressures thereon and are not under the control of the tilt lever 21. In this circumstance it will be seen that the rear presser font |1 will exert a greater pressure on the work than the front presser loot 16, the additional pressure being supplied by the compression spring 24, which is backecl up by the lateral arm 22 of the lifter.

It will be obvious that by proper adjustment of the eccentric collar 28 the additional pressure of the rear presser foot |1 may be lessened, until it becomes practically zero, whereupon both the presser feet will be made to press against a workpiece with equal pressures. As the eccentrc collar 28 is further adjusted, the front presser foot will be made to exert the greater pressure on the work, until the extreme condition is reached as shown in Fig. '1, wherein all of the pressure on the work is exerted by the front presser foot.

By this organization therefore, a very fiexible and minute control of the relative pressures and positions of the presser feet may he had, to suit various types of workpieces and speeds of sewing, etc.

It will be noted that, considering Fig. '1 wherein the tilt lever 21 is exerting control, when the front presser foot 6 encounters an obstruction such as a cross seam or other projecting part in a workpiece, the said foot may raise and surmount the said obstructlon in the normal manner. The raising of the front presser foot [8 in surmounting a cross seam causes the bracket II and presser bar to be raised approximately half the amount of the presser foot. During such movement both the tilt lever 21 and the rocker arms i will ulcrum about their respective pivots. The rear ends of the rocker arms |5 will act as if they were anchored and therefore not move, since the upper end 32 of the tilt lever 21 is immovably backecl up by the lifter arm 33 and since the front ends of the tilt lever 21 and rocker arm I5 will remain in engagement during the surmounting movement of the front presser foot. This is analogous to the action obtained f the tilt lever 21 is adjusted so as to not exert control during the sewing operation, as for instance with the adjustment of the eccentric collar shown in Figs. 4 and 5. It will be seen that. irom these flgures, as the front presser foot I8 raises to sul mount a cross seam, the rear ends of the rocker arms 15 will remain stationary during the surmounting movement due to the rear presser foot immovably resting on the work prior to the cross seam reaching it. Thus the surmounting action of the front presser fout 16 is substantially the same, whether the tilt lever 21 is controlling the relative pressures and positions of the presser feet, or whether the lever is inoperative for such eontrol.

The control of the presser feet either while in lowered work-engaging position or while in raised position out of engagement with the work is governed by a single adjustment, that of turning the ecoentric collar 28, and the said collar may be locked in any newly adjusted position by tight ening of the screw 29. It will be seen that during the operaton of the machine, and after the proper adjustment of the eccentric collar 28 has been made, the control of the presser feet is automatically accomplished by the actuation of the lifter which raises and lowers the presser bar and presser foot assemblage.

The above control of the presser feet is accomplished by few parts, namely the tilt lever 21, eccentric collar 28 and lifter arm 33, and these parts are of simple and economical construction ancl may be readily installed without requiring a great deal of additional space.

Variations and modifications may be made within the scope of this invention and portions of the improvements may be used without others.

I claim:

1. In a sevving machine, a frame; a presser bar; a pair of presser feet pivotally carried by the presser bar and located one ahead of the other; and adjustable means varying the pivotal relation of the feet to the presser bar for controlling the relative pivotal positions of the presser feet with respect to the presser bar.

2. In a sewing machine, a frame; a presser bar; a pair of presser feet pivotally carriecl by the presser bar and located one ahead of the other;

and adjustable means including a member connected with the frame and cooperable with the feet for controlling the relative pivotal positions of the presser feet when the latter are in lifted position out of engagement with a workpiece.

3. In a sewing machine, a frame; a presser bar; a pair of presser feet pivotally carried by the presser bar and located one ahead of the other; and adjustable means ineluding a member connectecl with the frame for controlling the relative pivotal positions of the feet and the pressures exerted on a worl piece by the presser feet when the latter are engaging the workpiece.

4. In a sewing machine, a frame; a presser bar; 2. pair of presser feet carried by the presser bar and located one ahead of the other; and adjust able means including a member connected with the frame and having a lifter for the presser bar, an eccentric pivot on the presser bar, and a lever carried by the pivot ancl engaging the said lifter for controlling the relative positions of the presser feet.

5. In a sewing machine, a presser bar; a pair of tandem-mounted presser feet carried by the presser bar; a lifter for the presser bar; and adjustable means including an eccentrc pivot carried by the presser bar and including a lever carried by the pivot and engageable with the lifter, for controlling the relative positions of the presser feet.

6. In a sewing machine, a frame; a springiirged presser bar en the frame; a pair ef presser feet pivetally carried by the presser bar and located ene ahead of the ether; a lifter mounted en the frame fer raising and. lowering the presser bar; and adjustable means carried on the presser bakte vary the pivetal relatien of the feet with respect te the presser bar and cooperable with the 1ifter, fer centrelling therelative pivetal positions of the presser feet with respect te the presser bar when the presser bar is in lewered er sewing positien.

7. In a sewing machine, a frame; a springurged presser bar en the frame; a pair of presser feet pivetally carried by the presser bar and. lecated ene ahead of the ether; a 1ifter meunted en the frame fer raising and lewering the presser bar; and adjustable means carried en the presser bar and ceeperable with the lifter, fer centreiling the relative pressures exerted. en a workpiece by the presser feet when the, presser bar is in iowered er sewing pesition.

8. In a sewing machine, a frame; a springurged presser bar en the frame; a pair of presser feet pivotaiiy carried by the presser bar and located ene ahead of the ether; a lifter meunted en the frame fer raising and lewering the presser bar; and adjustable means carried on the presser bar and coeperable with the lifter, fer increasing the pressure en a werkpiece by the front presser feet relative te the rear presser feet when the presser bar is in lewered er sewing pesitien.

9. In a sewing machine, a frame; a springurged presser bar en the frame; a rocker arm carried by the presser bar at the 1ewer end thereef; a pair of presser feet pivetally cennected te the rocker arm and lecated one ahead of the ether; a lifter meunted en the frame fer lowering and raising the presser bar; and adjustable means carriec en the presser bar and ceoperable with the lifter, the said means engaging the rocker arm fer contrelling the pestien of the latter and the reiative pestiens of the presser feet when the presser bar is in lewered 01' sewing pesitien.

10. In a sewing machine, a frame; a springurged presser bar en the frame; a rocker arm carried by the presser bar at the lewer end thereof a pair of presser feet pivotally cennected te the rocker arm and Iecated ene ahead of the ether; a lifter mounted. en the frame fer 1ewering and raising the presser bar; an eccentric pivot en the presser bar; and a lever carried by the givt and engaging the lifter and the rocker arm fer centrolling the relative positions of the presser feet.

11. In a sewing machine, a frame; a springurged presser bar en the frame; a rocker arm carried by the presser bar at the iewer end themaof; a pair of presser feet pivetally cennected te the rocker arm and located ene ahead of the ether; a lifter meunted en the frame fer Iowering and raising the presser bar; a piVet en the presser bar, adjustable thereen te different pesitiens; and a lever carried by the pivot and. at 0ne end engaging the lifter te be iifted thereby, the ether end of the lever engaging the rocker arm fer een troliing the position of the latter and the relative positiens of the presser feet.

12. In a sewing machine, a presser bar; a lifter fer the presser bar; a reckerarm carried by the presser bar at the lovver end thereef; a pair of presser feet pivotally cennected te the rocker arm and lecated ene ahead of the other; and means including an adjustably mounted member ceeperable with the rocker arm fer maintaining the front presser feet eitherhigher than, at the same ievel as, er lewer than the rear presser feet, depending en the adjustment of the said member, when beth presser feet are in 1ifted position out of engagement with a workpiece.

13. In a sewing machine, a presser bar; a lifter fer the presser bar; a rocker arm carried by the presser bar at the lower end thereof; a pair of presser feet pivotally cennected te the rocker arm and. lecated ene ahead of the ether; and means including a spring connected with the 1ifter and with the rear presser feet, and including an adjustably meunted member ceoperable with the rocker arm and lfter fer maintaining the front presser feet either higher than, at the same level as, er lewer than the rear presser feet, depend ing en the adjustment of the said member, when beth presser feet are in lifted pesition out of engagement with a werkpiece.

14. In a sewng machine, a presser bar; a rocker arm carred by the presser bar at the lower end thereef; a pair of presser feet pivetaily cennected te the rocker arm and iecated ene ahead of the ether; and means cennected with the frame and including an adjustably meunted member fer maintaining the front presser feet either hgher than, at the same leve1 as, er lower than the rear presser feet, depending on the adjustment of the said member, when both presser feet are in lfted pesitien out of engagement with a werkpiece.

15. In a sewing machine, a frame; a presser bar; a pair of presser feet pivotally carried by the presser bar and lecated one ahead of the other; means ceeperaele with ene of the presser feet fer impressing a yielding supplemental pressure thereon; and adjustable means including an adjustable pivot and a member connected with the frame fer centrelling the relative pivotal positiens of the presser feet under the supplemental pressure.

16. In a sewing machine, a pair of tandemmeuntecl presser feet; a lifter fer said feet; means connectecl with the lifter and ceoperable with one of the presser feet fer impressing a yieiding pressure thereen; and adjustable means ceeperable with the 1ifter fer centrolling the relative pesitions of the presser feet.

17. In a sewing machine, a presser bar; a pair of tandem-mounted presser feet carried by the presser bar; a lifter fer the presser bar; means connected with the lifter and ceeperable with one of the presser feet fer impressing a yielding pressure thereen; and adjustable means including an eccentric pivet carried by the presser bar and inciuding a lever carried by the pivet and engageab1e with the iifter, fer centrolling the relative pesitiens of the presser feet.

FRANCIS P. 'IAMBURRO.

REFERENCES CITED The feliowing references are ef record in the fi1e of this patent:

UNITED STA'IES PATENTS Number Name Date 1,279,088 De Vee Sept. 17, 1918 1,400,537 Gatcheli Dec. 20, 1921 1,988401 Thompsen Jan. 15, 1935

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