US3688712A

US3688712A - Walking presser devices for sewing machines

Info

Publication number: US3688712A
Application number: US133925A
Authority: US
Inventors: William J Edwards
Original assignee: Singer Co
Current assignee: SSMC Inc
Priority date: 1971-04-14
Filing date: 1971-04-14
Publication date: 1972-09-05
Anticipated expiration: 1989-09-05
Also published as: JPS4728161U; GB1382886A; SE370254B; JPS5317931Y2; FR2136069A5; IT950332B; BR7202252D0

Abstract

A presser device for a sewing machine which harnesses the needle reciprocatory movement alternately to shift into and out of work engaging position a work feeding foot which can move in the direction of feed of the work. The work feeding foot is biased into a position intermediate the total range of possible movement in the direction of feed, so that the work feeding foot can move with the sewing machine work feeding instrumentalities in either the forward or reverse directions of stitching and will be returned to the intermediate position between successive stitches.

Description

United States Patent Edwards Sept. 5, 1972 [54] WALKING PRESSER DEVICES FOR SEWING MACHINES [72] Inventor: William .1. Edwards, Freehold, NJ.

[73] Assignee: The Singer Company, 2, New York,

[22] Filed: April 14, 1971 [21] Appl.No.: 133,925

[52] US. Cl. ..ll2/2l2 [51] Int. Cl. ..D05b 27/04 [58] Field of 12/212, 207

[56] References Cited UNITED STATES PATENTS 3,468,272 9/1969 Shimobayashi ..1 12/21 2 3,472,187 10/1969 Kaplan etal ..]l2l212 Primary Examiner-Patrick D. Lawson Attorney-Marshall J. Breen, Chester A. Williams, Jr. and Robert E. Smith ABSTRACT A presser device for a sewing machine which harnesses the needle reciprocatory movement alternately to shift into and out of work engaging position a work feeding foot which can move in the direction of feed of the work. The work feeding foot is biased into a position intermediate the total range of possible movement in the direction of feed, so that the work feeding foot can move with the sewing machine work feeding instrumentalities in either the forward or reverse directions of stitching and will be returned to the intermediate position between successive stitches.

4 Claims, 6 Drawing Figures PATENTEI) SE1 5 1m sum 1 or 2 Fig. 3

William J. Edwards M @M/ )4] ATTORNEY WITNESS- v IRMA ur.m L

WKLKINGPRESSFJIDEVLIGES MRSEWING MACHINES BACKGROUNDOF THE INVENTION Prior 'known walking presser devices for sewing machines have .all provided work feeding feet capable of cooperating with the sewing machine work feeding instrumentalities in only the direction of feed of the work. This, of course, limits the .e'ffectivenessof the device since in the reverse direction -of work feed, the device does not aid the feeding mechanism :ofthe sewing machine.

SUMMARY QF It is an object .of the present invention'to provide a walkingpresser device for sewing machines including a work feeding foot which can move with the work feeding instrumentalities of the sewing machine :in :either the forward or reverse direction of travel of a work fabric. This object of the invention is attained by asupporting structure for the work feeding foot which, in addition to accommodating movement of the work feeding foot alternately into and out of engagement with the work fabric, includes a means for biasing the work feeding foot toward an intermediate position between stop abutments which limit the extreme forward and rearward positions of the work feeding foot. The work feeding foot when lowered intoengagement with the work in the intermediate position, is capable of moving with the sewing machine work instrumentalities in either the forward orreversedirection of work feed; and when the work feeding foot is raised, the biasing means can return the work feedingfoot into the intermediate position in readiness for the next succeeding workfeeding increment.

DESCRIPTION OF THE DRAWINGS The accompanying drawings illustrate a preferred embodiment of the invention in which:

FIG. I is a left hand end elevational viewofaportion of a sewing machine with-the frame partlybrokenaway and having a walking presser device of this invention applied thereto, showing a position of parts as the sewing'machine needle rises,

FIG. 2 is a right hand elevational view of the walking presser device of FIG. 1 with fragments of the sewing machine presser and needle bars,

FIG. 3 is a left hand elevational view of a portion of the walking presser device of FIG. I but with portions broken away,

FIG. 4 is a left hand elevational view of the walking presser device of FIG. 1 with fragments of the sewing machine but showing the position of the parts as the sewing machine needle reaches the bottom of its stroke,

FIG. 5 is an elevational view similar to FIG. 4 but showing the sewing machine needle descending alter completion of a forward work feeding movement, and

FIG. 6 is an elevational view similar to FIG. 4 but showing the sewing machine needle descending after completion of a reverse work feeding movement.

Referring to FIG. 1 a portion of a conventional sewing machine is illustrated including a work supporting bed 11, a standard 12 rising from the bed, and a bracket arm terminating in a sewing machine head l3 projecting from the standard and overhanging the bed I l. The presserbar 14 is endwise slidable in a'bushing 15 in the sewing head andis ordinarily adapted to carry a work pressing device which presses the work fabrics W against a throat plate 16 carried on the work supporting bed 1-]. The accompanying drawings illustrate an embodiment of this invention as an attachment adapted to be secured in place of the conventional presser foot on the presser bar as will be described below. Also jouma'lled for endwise reciprocation parallel to the presser bar in the sewing head 13 is a needle bar 17 having a-needle clamp 18 at its lower extremity including a needle clamping screw 19 'by which a sewing needle 20 may be fixed in the needle bar. The needle cooperates in a conventional fashion with a loop taker (not shown) arranged beneath the bed in the formation'of stitches.

FIG. 1 illustrates portions of a work feeding mechanism for advancing the work fabrics W transversely across the work supporting bed 1 I. This work feeding mechanism, which is wellknown in the sewing machine art, takes the form of a feed bar 30 arranged beneath the bed 11 and carrying a feed dog 31 which operates through slots 32 in the throat plate 16 alternatelyto rise into engagement with the work during the feed stroke and to drop out of engagement with the work during a return stroke. ,This known type of work feeding mechanism, which is referred to as a Drop Feed Mechanism," is driven from the sewing machine actuating mechanism by a feed lift rock shaft 33 having a rock arm 34 connected by a link 35 to the feed bar 30 to impart rising and falling movements to the feed dog and by a feed advance rock shaft 36 having a rock arm 37 pivoted as at 38 directly to the feed bar 30 to impart the feed advance and return strokes to the feed dog. The feed advance rock shaft 36 is formed with a rock arm 39 pivotally connected to a drive link '40 to which feed motion is transmitted by the sewing machine actuating mechanism. A feed regulating lever 42 is illustrated in FIG. I pivoted as at 43 in the machine standard l2 and carrying a slotted guide way 44. A slide block 45 pivoted as at 46 on'the feed drive link is slidable in the guide way 44. With this known construction for work feed regulation, the angular position at which the guide way 44 is set determines the magnitude and direction of the work feeding motion. An escutcheon plate 47 on the front of the machine standard may be provided with indicia for the stitch lengths corresponding to various positions of the feed regulating lever 42. The escutcheon 47 may also be formed with a depression 48 cooperating with an abutment 49 on the feed regulating lever that defines the zero stitch length position of the lever 42. As shown in FIG. I, when the feed regulating lever is turned to a position below the depression 48, the feed mechanism will be set to provide for a forward feed of the work, that is from right to left as viewed in FIG. I; and if the lever 42 were to be raised to a position above the depression, the effective work feeding stroke of the feed dog would occur during movement from left to right in FIG. I which is referred to as a reverse direction of feed.

The present invention is directed to correction of an inadequacy of the work feeding mechanism to advance all layers of certain work fabrics at uniform rates. With many fabrics the bottom ply in direct engagement with the feed dog 31 tends to be fed in greater increment than the upper ply which is in engagement with the presser device. The present invention provides a stationary presser foot 60 pivoted at 61 on a supporting bracket 62 having a seat 63 adapted to fit on the lower extremity of the presser bar 14. A clamp screw 64 is used to secure the bracket 62 to the presser bar. The term "stationary" is used with reference to the presser foot 60 to indicate that the foot does not move in the direction of feed of the work, the presser foot 60, however, is fee to be moved upwardly with the presser bar.

Arranged adjacent to the stationary presser foot 60 is a work feeding foot 70 which is carried by a spring arm 71 attached to a slide plate 72 formed with spaced parallel elongated slots 73. The slide plate 72 is slidably constrained alongside the bracket 62 by means of shouldered screws 74 which pass through the spaced slots 73 and are fastened in the bracket 62. The bracket 62 is formed with a recess 75 which is preferably arranged to extend parallel to the elongated slots 73 and as shown in FIGS. 1 and 4-6, is preferably covered by the slide plate 72. A pin 76 is carried by the slide plate 72 and projects into the recess 75. A pair of

coil springs

77 and 78 are arranged in the recess 75 one on each side of the pin 76 so as to bias the work feeding foot 70 into an intermediate position between two extreme positions of movement as determined by the

extremities

79 and 80 of the slots 73, which extremities define stop abutments dictating the total possible movement of the work feeding foot 70.

Referring particularly to FIG. 2 which illustrates the opposite side of the bracket 62 from that in which the recess 75 is formed, a presser lifting lever 90 is illustrated fulcrumed on a screw 91 fastened in the bracket 62. The presser lifting lever is formed with one arm 92 which extends over the work feeding foot 70 and may be provided with an anti-friction roller 93 thereon. At the opposite side of the fulcrum screw 91 the presser lifting lever is formed with an arm 94 which overlies a cam arm 95 formed on an operating lever 96 pivoted on a screw 97 fastened in the bracket 62. The operating lever 96 is formed with a bifurcated arm 98 which embraces the needle clamping screw 19 on the needle bar 17. The

fulcrum screws

91 and 97 may be threadedly engaged with the shouldered screws 74 through holes in the bracket 62.

As is known in the sewing machine art, drop feed mechanisms are conventionally timed so that the feed dog is raised into engagement with the work while the needle is elevated to a raised position free of the work fabrics. As shown in H0. 2, when the needle bar 17 is elevated, the operating lever 90 will be turned to rock the presser lifting lever 90 causing the anti-friction roller 93 to depress the work feeding foot 70. The force exerted to depress the work feeding foot will be applied in opposition to the downward thrust of the presser bar 14; and as a reaction to the application of this force, the stationary presser foot 60 will be lifted out of engagement with the work. During the work feeding stroke of the feed dog 31, therefore, whether it be in the forward or reverse direction, the feed dog 31 will be opposed by the work feeding foot 70 which because of the guide slots 73 will be free to move with the feed dog 31 in opposition to one of the

coil springs

77, 78 depending upon the direction of work feed. Both the upper and lower plies of work fabric therefore, will be subjected to the practically identical forces and uniformity of feed of each of the plies will result.

When the needle descends as shown in FIG. 4 the operating lever 96 will release the presser lifting lever and the force will be removed depressing the work feeding foot 70. The stationary presser foot 60 will return downwardly into the work engaging position and the resilience of the spring arm 71 supporting the work feeding foot will cause the work feeding foot to be elevated above the work. The coil springs 77, 78 will then be permitted to return the work feeding foot into an intermediate position between the opposite extreme positions as illustrated by the

slot extremities

79, 80. The feeding foot will then be arranged in readiness for the next feed stroke. As shown in FIGS. 3 and 4 the coil springs 77, 78 are preferably of slightly different lengths with the coil spring 77 being shorter. As a result, the intermediate position into which the

springs

77, 78 return the work feeding foot after each feeding stroke is not centered between the abutment surfaces 79, but is closer to the abutment surfaces 79 which limits the movement of the work feeding foot in the reverse direction of work feeding. By this arrangement a greater extent of feeding motion is made possible for the work feeding foot in the forward direction of feeding, and this has been found to be advantageous because sewing machine work feeding mechanisms are operated in the forward direction of feeding the higher percentage of the time.

it will be appreciated that the arrangement of

springs

77, 78 for returning the work feeding foot to an intermediate position so that the device of this invention may be used to augment either a forward or a reverse direction of work feeding will have utility not only for devices such as disclosed in the accompanying drawings which are organized as attachments for sewing machines, but will serve advantageously for such devices as may be incorporated permanently into sewing machine constructions.

Having set forth the nature of this invention, what is claimed herein is:

l. A presser device adapted for use with a sewing machine having a presser bar and a needle bar, said presser device comprising a presser foot, a work feeding foot, means supporting said work feeding foot for movement relatively to said presser foot along a work feeding path, spaced abutment means defining opposite extreme positions of movement of said work feeding foot along said work feeding path, means for shifting said work feeding foot alternately into and out of work engaging position and means efi'ective when said work feeding foot is shifted out of work engaging position for returning said work feeding foot along a work feeding path into a position intermediate said extreme positions defined by said spaced abutment means.

2. A presser device as set forth in claim I in which said presser foot includes attachment fastening means adapted to be secured to a sewing machine presser bar, and in which said means for shifting said work feeding foot out of work engaging position comprises an operating lever having means for connection with a sewing machine needle bar.

3. A presser device as set forth in claim 1 in which said means effective to return said work feeding foot to which the intermediate position into which said spring means biases said work feeding foot is closer to said abutments defining the extreme position of movement of said work feeding foot in the reverse direction of work feed.

Claims

1. A presser device adapted for use with a sewing machine having a presser bar and a needle bar, said presser device comprising a presser foot, a work feeding foot, means supporting said work feeding foot for movement relatively to said presser foot along a work feeding path, spaced abutment means defining opposite extreme positions of movement of said work feeding foot along said work feeding path, means for shifting said work feeding foot alternately into and out of work engaging position and means effective when said work feeding foot is shifted out of work engaging position for returning said work feeding foot along a work feeding path into a position intermediate said extreme positions defined by said spaced abutment means.

2. A presser device as set forth in claim 1 in which said presser foot includes attachment fastening means adapted to be secured to a sewing machine presser bar, and in which said means for shifting said work feeding foot out of work engaging position comprises an operating lever having means for connection with a sewing machine needle bar.

3. A presser device as set forth in claim 1 in which said means effective to return said work feeding foot to said intermediate position comprises spring means biasing said work feeding foot away from each of said abutment means.

4. A presser device as set forth in claim 2 in which the spaced abutments define extreme positions of movement of said work feeding foot in the forward and reverse directions of work feeding respectively, and in which the intermediate position into which said spring means biases said work feeding foot is closer to said abutments defining the extreme position of movement of said work feeding foot in the reverse direction of work feed.