US1213788A - Sewing-machine. - Google Patents

Description

JOHN V. ALLEN, OF SOUTH WEYMOUTH, AND EDWARD E. ORR,-OF WEYMOUTH, MASSA- CHUSETTS, A-SSIGNORS TO UNITED SHOE MACHINERY COMPANY, OF PATERSON, NEW JERSEY, A CORPORATION OF NEW JERSEY. I

SEWING-MACHINE.

Specification of Letters Patent.

Patented Jan. as, iota.

Application filed November 14. 1914. Serial No. 872,119.

Norfolk and Commonwealth of Massachusetts. have invented certain new and useful Improvements in Sewing-Machines; and we hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to sewing machines of the type which employ a four-motion work feeding device by which the work is carried forward step by step.

More particularly the invention relates to Y an improved mechanism one purpose of which is to prevent the feed foot of the fourmotion feeding mechanism from engaging the presser foot when the machine is running without work. y In mechanisms used heretofore for pre venting the'feed foot from engaging the presser foot, when the machine is running withoutavork, for instance that illustrated in Letters Patent of the United States to Albert E. Johnson No. 1089,4573, dated March 10, 1914, the stop forming one of the elements of the mechanism has only a vertical movement and is engaged by a feed bar which has one movement at substantially a right angle thereto. In such a construction it has been found that the rubbing or drag of the stop onthe feed bar racks the whole head of the machine and especially the ver-. ticallv movable presser foot bar which carries the stop. This constant racking causes the bar to wear fast and destroys its bearings. Further. after the bearings have become worn the stitching mechanism is interfered with. thus causing the thread to break. In some special work, for instance securing together the two flaps of an insole as described in said Johnson patent, this strain is doubly injurious as the side strain on the presser foot bar is continual, the rubbing of the feeding device past the stop occurring at each food movement, whether or not work is in the machine. I &

The object of the present invention is to improve the mechanism 'fo r- 11o pu m referred to heretofore used by providing means for preventing wear and strain on the presser foot bar and other machine parts.

In accordance withthis object the invention contemplates the provision of a wear plate which partakes in the vertical movement of the feed bar but is held against lon- 'gitudinal movement therewith. One form of such plate may be a lever,' the active end of which has a long radius of movement and which is interposed between the stop on the presser foot bar and the feed foot bar. In the preferred form of the invention the usual four-motion feed bar contacts with the lower face of the lever near its free end and the stop on the presser foot bar engages the upper face of the lever at a point substantially opposite its point of contact with the feed bar. By this means the wear and thrust due to the feeding and return strokes of the feed bar is absorbed by the lever and the thrust on the stop is in a vertical direction only caused by the rise'and fa l of the lever as the feed bar rises and falls. All side strain on the bearings of the presser foot bar is thus eliminated. The lever is conveniently made of two vertically adjustable parts to accurately fit it in the machine for the particular class of work beingopcrated upon. To the accomplishment of the above object and such others as may hereinafter appear. the invention comprises the devices, combinations and arrangements of parts hereinafter described- The preferred form of invention is i lustrated in the accompanying drawings. in wh ch:

Figure 1 is an end'elevation of a Wilcox and Gibbs domestic machine equipped for securing together the two contiguous flaps of an insole, in accordance with the disclosure in said Johnson patent hereinbefore referred to; having also the present improved mechanism fitted thereto. and F ig. 2 is a detail view showing an end elevation of the improved mechanism and a portion ofthe feed bar in their relation when the work has just been placed in the machine and the feed and particularly pointed out in the appended-c aims.

. is-provided with an extension 13 for guiding its movements, said extension being held to the machineframe by a washer 15.

-'The work table 24; is removablyheld in a casting 25 with its front edge slightly in ,advance ofthe path of operation of the needle 2. In operating up'oniinsoles the edge .fiap of the insole. in working position, rests upon the. work table, which presses well into the shoulder at the baseof the feather, and

the channel fiap is pressed upon by the presser foot 18. A ,portionof the two flaps of an insole in working position during the feedis illustrated in Fig. 1.. f The small area of the work table in the illustrated machine leaves the thread hook 4- exposed and, owing to the positionoftheinsole in the machine unless some protection be provided, the thread hook in its rotation, is liableto injure either the marginal portion of the sole by engagement therewith or the hand of the operator who directs the feed of the work through the machine. To pre-'- vent such injury, the thread hook is covered with a cap or guardi28 which is supported on the casting 25. The guard 28 efi'ectivel houses the thread hook and shields the work and also the operative.

In order to maintain the two flaps of the insole in stitch receiving position during the operation of the stitch forming mechanism,

the machine is also provided with a work. positioning device or guide roll (not shown) mounted on the end of the arm 32 of a bellcrank lever 32-36 which is pivoted at 35.

This guide exerts a pressure on the unchanneled a surface of the insole opposite the, flaps, through the medium of the spring 37. The other arm 36 of the bell crank lever which supports the work. ide is connected ,with a second bell-crank ever 38 which in turn is connected with a 1ever44.

7 As the presser foot 18 must be lifted before the work can readily be removed from the machine, the lever 44 is provided to .en-

gage a shoulder 46 on the lower end of the presser foot bar 20. Also the bell-crank lever 38 is connected to a treadle so that. by

a the depression of I the treadle, the lever 44 contacts with the shoulder 46 and raises the presser foot 18. Simultaneously with the raisingof the pressenfoot the guide roll,. connected to the bell-crank lever 32-36,

-l9-as a center. of the end of the leverwhere thelug 26 is located is so long compared to the amount of vertical movement imparted by the feed 7 removed from the insole and thus the presser foot and guide roll are opened up to remove or insert work into the machine.

' The features of the illustrated machine relating to stitching the two flaps together, the device to hold the insole institch receiving position, and the mechanism for opening up said device to receive or remove the insole are not claimed herein as they are fully described and claimed in said Johnson patent hereinbefore referred to.

Referring now more particularly to the novel feature forming the subject matter of the present invention it is seen that in distinguishment from said Johnson patent the machine is provided with a thrust absorbing lever 21 which is pivoted to the machine frame at 19. This lever, which is in the form of a flat plate, is mounted above the feed bar 12 and has :1 lug 26 on its under face at its free or active end which rests upon the upper face of the feed bar. By means of this construction the movement of the feed bar in its elliptical path causes the lever to oscillate slightly about its pivot The radius of movement bar that the free end of the lever is caused to move in a path substantially parallel to the axis of the presser foot bar. The lever 21 may therefore be correctly termed an absolute thrust-absorbing lever as it wholly pre-,

vents any side thrust from the feed bar being transmitted to the presser foot bar.

The lever 21is preferably bifurcated having the upper and lower arms 30 and 31."

The arm 31 carries the lug 26 upon its end. The arm 30 is attached atone en to the arm 31 by set screws 23 and carries near its free end an adjustable set screw 27 which is threaded through the arm and because of .the resilience of the arm permits of its adjustment relative to the arm 31. This ad justment is provided to care for different thicknesses of work to be operated upon and ,to govern the relation of the feed foot to the presser foot. The presser foot bar 20 is mounted, a usual, in bearings in the frame 65 and car- ,ries the presser foot 18 at its lower end.

This presser foot is held down upon the work by a spring62 mounted upon the frame and bearing upon a loose wear collar 63 which .rests on the usual fixed collar 64 on the presser foot bar. Extending downwardly from the presser foot 18 is a stop 56 which is adapted to engage the free end of the'arm 30 on the lever '21. Thus the rise and fall of the endof the lever 21 in its substantially vertical path will cause the stop 56, engaged bythe lever, to impart a vertical movement'onlv to the presser foot bar '20. By virtu'e'of this construction there thrown into operation and the four-motion intense am:

is no strain on the presser foot bar at right angles to its axis and the side drag and thrust on the bearings of the bar resulting from the construction illustrated in said Johnson patent are eliminated. The thrust due to the translation of the feed bar is all absorbed by the lever 21 at its lug 26 and bearing 19, and these parts may be suitablyconstructed of hardened material to provide .for such Strain.

from their normal positions when nowork.

is in the machine and places the spring 62 under compression. This position is shown by Fig. 2. The stitch forming mechanism is feed device carries the work forward after eachstitch is formed. After the feed foot has risen to grip the work ready for the forward movement, the lever 21 is brought into engagement with the stop 56 (see Fig. 1) and the continued upward movement of the feed bar to clear the work from the table, acts through the stop 56 to raise the presser foot at the same time. The pressure from the spring 62is thus transmitted to the feed bar and the work is allowed to go forward without undue friction. This position of the parts is shown in Fig. 1. The stitch forming mechanism operates continuously so that, there are periods when there is no work in the machine and at such time if it were not for the stop 56 the feed foot in rising would strike the presser foot which is then held against the table by its spring 62,-

and injure the machine.

It will be seen from Fig. 2 that when no work is in the machine, the rise of the feed bar will cause an engagement of the lever 21 with the stop 56 before the feed foot reaches the presser foot. It is thus seen that the present construction contains all the advantages described in said Johnson patent hereinbefore referred to while at the same time relieving the presser foot bar from all side strain.

The nature and scope of the invention having been indicated and its preferred embodiment specifically described, what. is

' claimed as new, is:

1. A. sewing machine, having, in combination. a presser foot bar, ajpresser foot on said bar. stitch forming mechanism, feeding means. means to actuate the feeding means, a stop mounted onthe presser foot bar to control the movement of the presser foot, and a thrust absorbing member between the feeding means and stop arranged to absorb' the thrust of the feeding means on the presser foot bar in the direction of feed. 4

2. A sewing machine, having, in combination, a founmotion feed device, a presser foot bar, a presser foot mounted on the presser foot bar to co-act with the feeding device, and movable means mounted on the machine frame and actuated by the feeding device independently of the work to directly transmit the vertical motion only of the feeding device to the presser foot.

3. A sewing machine having, in combination, work feeding means, mechanism to actuatethe feeding means, a presser foot bar mounted to reciprocate in a-direction normal to the line of feed of the work, connections between the presser foot bar and the feeding means for liftingthe presser foot bar during the advancing movement of the work, 35

.a lever pivoted to the machine framewith a fr'e'e'eiid interposed betweenthe presser foot stop and feeding means whereby the feeding means acts through said lever'to actuate the presser foot.

5. A sewing machine, having, in combination, a four-motion feeding means, means for operating the feeding means, a presser foot coperating with the feeding means to clamp the work and movable in a direction substantially normal to the direction of feed, a stop mounted on the presser foot bar, a lever pivoted to the machine frame with a free end interposed between the presser foot stop and feeding means whereby the feeding means acts through said lever to actuate the presser foot, and'means for adjusting said lever to vary its distance from the stop.

6. A sewing machine, having, in combination, a work feeding member, means to operate said member, a lever pivoted to the machine frame-With its free end bifurcated and resting on the feeding member. an adjusting device for the bifurcated end of the lever, a presser foot cooperating with the feeding member, and a stop on the presser foot bar adapted to engage the free end of v ment of the feeding device, e presser foot on feeding device to eliminate the thrust in the said bag, 61nd a thruedt abserbing niemfbeg indirection of feed from the presser foot bar. 10 terpose etween sai means andt e'ee in Y P T device, movebly mounted independently 0% 5 the presser foot bar. to impart the vertical J movement of the feeding device to the Witnesses:

presser foot bar while fixed from perticipe- 1 A. G. BALDWIN, 'tion in the longitudinal movement of the C. H. "WHITMAN.

93i053 02 this intent may be ebtefiaezl fer fiveeents each. w edxemng the Commissioner oi" Patents,

' washtmgtemfifl.

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