US3613609A

US3613609A - Feed mechanism and presser foot arrangement

Info

Publication number: US3613609A
Application number: US857929A
Authority: US
Inventors: Robert A Hayes; James A Frendreis
Original assignee: Union Special Machine Co
Current assignee: Union Special Machine Co
Priority date: 1969-09-15
Filing date: 1969-09-15
Publication date: 1971-10-19
Anticipated expiration: 1988-10-19

Abstract

A multiple needle felling machine including a main feed bar and a differential feed bar connected, respectively, to a main feed dog and a differential feed dog each having several rows of teeth with one row being higher than the other rows and the teeth on the respective feed dogs facing in opposite directions. A multiple-section presser foot cooperates with the feed dogs and includes a spring-loaded yielding section to clamp the thread chain to insure nonskipping at the start of sewing operations.

Description

United States Patent Robert A. Hayes Franklin Park; v

James A. Frendreis, Chicago, both of III. 857,929

Sept. 15, 1969 Oct. 19, 1971 Union Special Machine Company Chicago, Ill.

Inventors Appl. No. Filed Patented Assignee FEED MECHANISM AND PRESSER FOOT ARRANGEMENT 17 Claims, 14 Drawing Figs.

US. Cl 112/235, 1 12/216 Int; Cl ..D05b 27/02, D05b 29/00 Field of Search l 12/235-240, 216, 215

{56] References Cited UNITED STATES PATENTS 2,370,738 3/1945 Kucera l l2/235 2,627,240 2/1953 Johnson et al. 112/235 2,671,422 3/1954 ,Tamburro et al. l 12/2'35 Primary Examiner- Patrick D. Lawson An0rney-Diller, Brown, Ramik & Holt ABSTRACT: A multiple needle felling machine including a main feed bar and a differential feed bar connected, respectively, to a main feed dog and a differential feed dog each having several rows of teeth with one row being higher than the other rows and the teeth on the respective feed dogs facing in opposite directions. A multiple-section presser foot cooperates with the feed dogs and includes a spring-loaded yielding section to clamp the thread chain to insure nonskipping at the start of sewing operations.

PATENTEDUBT 19 I97! 3,613, 09

-- SHEET10F'3 lNVE/VTURS QOBEET A. HAYES JAMES A.FRENDRE|$ v ATTORNEYS WWW ml 3,613,609

SHEET 2 OF 3 /NVN TURS RUBEWT A. HAYES 6"- JAMES A. FRENDREIS ATTORNEYS km uiffnum 1s l97| sum 3 0F 3 yawn INVENTUR5 ROBERT A. HAYES 6 JAMES A.FRENDREIS ATTORNEYS FEED MECHANISM AND PRESSER FOOT ARRANGEMENT CROSS-REFERENCES TO RELATED APPLICATIONS BACKGROUND OF THE INVENTION 1. Field of the Invention The new feed mechanism and presser foot arrangement herein disclosed is particularly adaptable for use on a differential feed-off-the-arm machine and can also be employed on a flat bed machine with a differential feeding mechanism.

2. Description of the Prior Art Previously known types of feed-off-the-arm machines were designed for heavy weight materials such as denim or overall material. Such machines are not completely satisfactory for use with lightweight woven materials or lightweight knit materials.

The presser foot in some known types of machines includes a yielding section on the rear portion of the presser foot. Such known yielding sections were only able to move up or down and such movements are not entirely satisfactory.

Various types of presser foot arrangements have been devised but when the presser foot was raised to insert the material, the whole foot would lift off of the throat plate. In doing this, the thread chain is not held on the throat plate in a line directly behind the needle slots, but is free to lay in any direction from the needle slots. This results in skipping of the first few stitches on the material.

SUMMARY OF THE INVENTION The main object of the present invention is to provide pucker-free felled seams.

The feed-off-the-arm machine herein'disclosed is of the same type as that which has been previously disclosed in U.S. Pat. No. 3,416,473.!Idwever, the present machineis particularly designed for lightweight woven materials and some lightweight knit materials such as the type used for men's dress shirts.

A main feed dog and a differential feed dog are disclosed as having one row of their teeth stepped up in relation to the other rows of teeth. The teeth on the main feed dog are facing in the normal manner in the direction of the feeding stroke. The teeth on the differential feed dog are facing against the direction of the feeding stroke. When sewing woven materials the differential feed dog is set for a shorter travel than the main feed dog. The combination of the shorter travel and the oppositely facing teeth of the differential feed dog tends to hold back the material while the greater stroke of the main feed dog will therefore cause the material to be slightly stretched as it is being sewed. The thread is also in a slightly stretched condition as the stitches are being formed. Upon leaving the feed dogs both the material and the stitching will return to their normal conditions resulting in a flat pucker-free seam.

When sewing knit material, the differential feed dog is set for a slightly greater travel than the main feed dog. This will cause the material to be slightly gathered as it is being sewed. The reason for gathering when sewing knit material is that, as the operator is presenting the material to the machine, the material has a tendency to stretch slightly. Therefore, the feed dogs will gather the material partly back to its original condition while it is being sewed. Here again, the thread is in a slightly stretched condition as the stitches are formed. Therefore, upon leaving the feed dogs, the material will fully return to its normal condition along with the thread. Thus, the result will be a flat pucker-free seam.

A further object of the present invention is to provide a presser foot made up of three sections, each having a stepped portion corresponding to the stepped row of teeth on the feed dogs. The stepped portions on both the presser foot and feed dogs serve to produce a straight seam free from any curvature.

Another object of the present invention is -.to construct a presser foot so that more pressure is applied on the front section than on the remaining sections. For example, with the present invention, if 20 pounds of pressure is applied to the presser bar the resulting pressure on the presser foot will be I 0 pounds on the front foot section and only 5 pounds on therear foot section and middle foot section. This greater pressure applied by the front section against the differential feed dog further serves to hold the material back while the main feed dog is stretching it.

A further object of the present invention is to provide an improved presser foot having a yielding section on the rear portion thereof wherein the yielding section is permitted to float, or pivot, on a pair of springs in the rear portion of the'presser foot.

A further object of the present invention is to provide an improved presser foot which aids the operator in beginning the stitching on the material. The improved presser footis constructed so that the operator is able to lift the front foot section while the other foot sections remain in contact with the throat plate. In this way, the yielding section on the rear foot portion clamps the'thread chain flat against the throat plate in a line directly behind the needle slots. Therefore, no skipping will result during the first few stitches on the material. The operator can also lift the whole foot off of the work if she pleases by applying more pressure to the foot treadle or other means.

Another object of the present invention is to provide a novel method and apparatus by which a main feed dog and a differential feed dog combine with the novel presser foot to produce pucker-free seams.

A still further object of the present invention is to provide a combination of a plurality of feed dogs having teeth opposing each other and having one row of teeth on each feed dog stepped up and in line with each other.

With the above and other objects in view that will hereinafter appear, the nature of the invention will be more clearly understood by reference to the following detailed description, the appended claimed subject matter andthe several views illustrated in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a fragmentary side elevational view, partly in sec tion, of the sewing machine employing the present invention.

FIG. 2 is a partial plan view of the work-supporting arm showing the arrangement of the feed dogs in the throat plate.

FIG. 3 is an elevational view of the presser foot as shown in FIG. 1.

FIG. 4 is a plan view of the presser foot shown in FIG. 3.

FIG. 5 is a plan view partly in section taken along line 5-5 of FIG. 3.

FIG. 6 is an elevational view partly in section along line 6- 6 of FIG. 3.

FIG. 7 is a sectional view taken along line 7-7 of FIG. 3.

FIG. 8 is a sectional view taken along line 8-8 of FIG. 3.

FIG. 9 is a sectional view taken along line 9-9 of FIG. 3.

FIG. 10 is a detail view in elevation of the main feed dog.

FIG. 11 is a sectional view taken along line 11-11 of FIG. 10.

FIG. 12 is a detail view in elevation of the differential feed dog.

FIG. 13 is an end view of the differential feed dog of FIG. 12.

FIG. 14 is a fragmentary sectional view taken along line 14-14 of FIG. 2, and including the workpiece material and a section of the presser foot.

DESCRIPTION OF THE PREFERRED EMBODIMENT The sewing machine frame and the various driving mechanisms therein are the same as those disclosed in U.S. Pat. No. 3,416,473.

Within the work supporting arm extends a looper rock shaft 11 carrying looper holders 12 at one of its ends. Loopers 13 are mounted in the looper holders 12 within the work supporting arm 10. These loopers are located beneath the needles 14 which are carried by the needle bar 15. The needle bar, in turn, is slidably carried in the needle head 16.

Also within the arm' 10 extends a differential feed bar 17 which carries a differential feed dog 18 at its front end. The feed dog 18 is secured by a screw 19 to the feed bar 17. The feeddog is adjustable up and down by means of the elongated slot 20. v

A main feed bar 21 is provided aridalso extends within the arm 10. To the front endofbar 21 is secured, by a screw 22, a main feed dog 23. An elongated slot 24 in the main feed dog 23 allows the feed dog to be adjusted up or down. The feed bars 17 and 21, and their

feed dogs

18 and 23, are driven and adjusted in a manner as that which has been previously described in U.S. Pat. No. 3,416,473.

The front end of the work supporting arm 10 supports a throat plate 25. The throat plate is provided with a raised or stepped up portion 26 along one side. This step portion 26 has a feed slot 27 disposed longitudinally therein. The main or lower surface 28 of the throat plate has a series of parallel feed slots 29. The feed slots 29 are substantially as long as the feed slot 27. The throat plate 25 also has two needle slots 30 located and spaced to correspond with the needle 14.

The feeding surface of the main feed dog 23 has several rows of teeth with one row of teeth 31 being slightly higher than the other rows of teeth 32. The higher one row of teeth 31 registers in the rearward portion of the feed slot 27 of the throat plate 25 with the other rows of teeth 32 registering in therearward portion of the feed slots 29.

The feeding surface of the differential feed dog 18 has several rows of teeth with the teeth facing opposite the direction of the main

feed dog teeth

31 and 32. One row of teeth 33 is slightly higher than the other rows of teeth 34. The higher row of teeth 33 registers in the forward portion of the feed slot 27 with the other rows of teeth 34 registering in the forward portion of the feed slots 29. i

A three section presser foot 35 is mounted above the throat plate 25 to a'presser bar 36. The three sections of the presser foot cooperate with the

feed dogs

18 and 23 to produce the flat pucker-free felled seam that is desired.

' A presser foot shank 37 is secured to a presser bar 36 by a screw 38 and has two downwardly and forwardly extending

legs

39 and 40. These legs are pivotally secured, by screws 41, intermediate the ends of

arms

42 and 43 of a presser foot bracket 44. At the forward ends of

arms

42 and 43 there is pivotally secured, by first pivot screws 45, a front presser foot section 46. This front foot section 46 is located above and cooperates with the differential feed dog 18. The bottom of front presser foot section 46 is made up of two

separate surfaces

47 and 48. Surface 47 cooperates with the lower rows of teeth 34 on the differential feed dog 18 while surface 48 is cut to a depth that will correspond to the higher row of teeth 33 on the differential feed dog 18.

The rearward end of presser foot bracket 44 embraces a hinged section 49 (FIG. 8) intermediate its ends and is pivotally secured thereto by a pivot screw 50. At the forward end of the hinged section 49 there is pivotally secured, by a screw 51, a second or middle presser foot section 52. This presser foot section 52 is located immediately behind and in line with the front presser foot section 46. it also is above and in cooperation with the front portion of the main feed dog 23. The foot section 52 is provided with needle slots 53 located to coincide with the needle slots 30 in the throat plate 25. The bottom of foot section 52 is also made up of two separate surfaces 54 and 55 in order to correspond to the difference in height of the rows of

teeth

32 and 31 on the main feed dog 23.

At the rearward end of hinged section 49 there is pivotally secured, by screw 56, a rear presser foot section 57. This presser foot section 57 is immediately behind and in line with the middle presser foot section 52 and is located above the rear portion of the main feed dog 23 for cooperation therewith. The rear presser foot section 57 carries a springloaded yielding section 58 confined in a slot 59 on the bottom of the foot section 57. A pair of springs 60 and 61 serve to force the yielding section 58 toward the work. Springs 60 and 61 are confined in bores in the bottomof the hinged section 49 and pass through holes in the bottom of the rear presser foot section 57. The yielding section 58 has upwardly and inwardly turned lips 62 at each end which serve to keep it attached to the foot section. On the bottom of the foot section 57 there are first and second separate

material engaging surfaces

63 and 64 that correspond to the difference in height of the rows of teeth 32, Men the main feed dog 23. Slot 59 is cut to a greater depth than surface 64 so that as a seam is being sewed the yielding section 58 can be pushed up so that it will be in the same plane as the surface 64.: After a piece of material has been sewed, the yielding section 58 will be pushed down to clamp the thread chain to insure against skipping at the beginning of the next piece of material.

One end of a hold-down spring 65 is fitted into a bored hole 66 in the end of the presser bar 36. The other end of the spring 65 fits over a threaded pin 67 secured'in the top surface of the hinged section 49. The pin 67 and the spring 65 are located on the center line of the presser bar 36. The spring 65 applies a downward pressure on the hinged section 49 and, in turn, to the

presser foot sections

52 and 57. Therefore, as the presser bar 36 is raised slightly, the presser foot shank 37 will begin to raise the presser foot bracket 44 pivoting on screws 41. As the presser foot bracket 44 raises, it will pivot on the screw 50 and will also raise the front presser foot section 46. Because of the pressure of spring 65, the middle and rear.

presser foot sections

52 and 57 will not be lifted and therefore will enable the yielding sections 58 to clamp the thread chain to insure nonskipping of the first few stitches at the beginning of the next piece of material.

The preferred form on the invention has been described and illustrated, it being understood that the purposes of the invention can also be accomplished by minor changes in individual parts and arrangements within the'spirit and scope of the invention.

We claim: v l

1. In a sewing machine, a presser foot having a plurality of sections including a front foot section, a rear foot section, and a middle foot section, means for connecting the respective foot sections to a presser bar, said means including arm means having a forward end and a rearward end, leg means pivotally connected to said arm means, first pivot means connecting said front foot section to said forward end of said arm means, and second pivot means connecting said rear foot section and said middle foot section to said rearward end of said arm means.

2. Apparatus as in claim 1 wherein said second pivot means includes a hinged section having a forward end and a rearward end, and means pivotally connecting said middle foot section to the forward end of said hinged section and said rear foot section to the rearward end of said hinged section.

3. In a sewing machine, a presser foot having a plurality of sections including a front foot section and a rear foot section, a presser bar connected to said presser foot for applying pressure thereto, distributing means for distributing more of said pressure to said front foot section than to said rear foot section, said distributing means including leg means extending downwardly from said presser foot, arm means having a forward end and a rearward end, means pivotally connecting said arm means intermediate said forward end and rearward end to said leg means, first pivot means connecting said front foot section to the forward end of said arm means, a hinged section having a forward end and a rearward end, second pivot means connecting said hinged section to said rearward end of said arm means, a middle foot section, means connecting said middle foot section to the forward end of said hinged section, and means connecting said rear foot section to the rearward end of said hinged section.

4. In a sewing machine, a presser foot having a plurality of sections including a front foot section and a rear foot section, a presser bar connected to said presser foot for applying pressure thereto, distributing means for distributing more of said pressure to said front foot section than to said rear foot section, means for raising said front foot section following a sewing operation, and holddown means for precluding upward movement of said rear foot section.

5. Apparatus as defined in claim 4 wherein said holddown means comprises spring means operatively disposed intermediate said rear foot section and said presser bar.

6. In a sewing machine, a presser foot having a plurality of sections including a front foot section and a rear foot section, a presser bar connected to said presser foot for applying pressure thereto, and holddown means operatively disposed between said presser bar and said rear foot section for precluding movement of said rear foot section when said presser bar is operated to raise said front foot section, said rear foot section including a yielding section located in spaced relation on the underside thereof, and biasing means urging said yielding section downwardly from said rear foot section for engagement with a thread chain between sewing operatrons.

7. Apparatus as defined in claim 1 including a main feed dog having material-feeding teeth thereon facing in the direction of feed, and a differential feed dog having material-feeding teeth thereon facing opposite the direction of the teeth on said main feed dog; said main feed dog being located for cooperating with said rear foot section, said differential feed dog being located for cooperating with said front foot section.

8. In a sewing machine, a presser foot having a plurality of sections including a front foot section and a rear foot section, a presser bar connected to said presser foot for applying pressure thereto, distributing means for distributing more of said pressure to said front foot section than to said rear foot section, a main feed dog having material-feeding teeth thereon facing in the direction of feed, and a differential feed dog hav-' ing material-feeding teeth thereon facing opposite the direction of the teeth on said main feed dog; said main feed dog being located for cooperating with said rear foot section, said difierential feed dog being located for cooperating with said front foot section.

9. In a sewing machine, a presser foot having a plurality of sections including a front foot section and arear foot section, a presser bar connected to said presser foot for applying pressure thereto, holddown means operatively disposed between said presser bar and said rear foot section for precluding movement of said rear foot section when said presser bar is operated to raise said front foot section, a main feed dog having material-feeding teeth thereon facing in the direction of feed, and a differential feed dog having material-feeding teeth thereon facing opposite the direction of the teeth on said main feed dog; said main feed dog being located for cooperating with said rear foot section, said differential feed dog being located for cooperating with said front foot section.

10. In a sewing machine including a presser foot, said presser foot comprising first and second material-engaging surfaces separated by a slot extending upwardly therebetween, a yielding section confined in said slot, spring means confined in said slot between said yielding section and said presser foot for urging said yielding section toward the work, said spring means engaging said yielding section at a rearward portion thereof for allowing a forward portion of said yielding section to be raised higher than said rearward portion.

11. Apparatus as defined in claim 10 wherein said yielding section includes intumed lip means engaging a portion of said presser foot for retaining said yielding section with said slot means.

12. In a sewing machine, a main feed dog having a plurality of rows of material-feeding teeth thereon with all of the teeth facing in a first direction, and a differential feed dog having a plurality of rows of material-feeding teeth thereon with all of the teeth facing in a second direction from said first direction, at least one row of teeth on said main feed dog and at least one row of teeth on said differential feed dog being stepped up from the remaining rows of teeth.

13. Apparatus as defined in claim 12 wherein the stepped rows of teeth on said main feed dog and said difi'erential feed dog are in line with each other.

14. Apparatus as defined in claim 12 including a presser foot having a plurality of sections including a front foot section and a rear foot section, said main feed dog being located for cooperating with one of said plurality of sections, and said differential feed dog being located for cooperating with another one of said plurality of sections.

15. Apparatus as defined in claim 13 including a presser foot having a plurality of sections including a front foot section and a rear foot section, said main feed dog being located for cooperating with one of said plurality of sections, and said differential feed dog being located for cooperating with another one of said plurality of sections.

16. A method of producing a pucker-free seam when sewing woven materials comprising the steps of providing a main feed dog with material-feeding teeth thereon facing in the direction of material feed, providing a differential feed dog with material-feeding teeth thereon facing in the direction opposite from the direction of material feeding, and controlling the length of travel of said diflerential feed dog so it is shorter than the length of travel of said main feed dog.

17. A method of producing a pucker-free seam when sewing knit materials comprising the steps of providing a main feed dog with material feeding teeth thereon facing in the direction of material feed, providing a differential feed dog with material-feeding teeth thereon facing in the direction opposite from the direction of material feeding, and controlling the length of travel of said differential feed dog so it is longer than the length of travel of said main feed dog.

Claims

6. In a sewing machine, a presser foot having a plurality of sections including a front foot section and a rear foot section, a presser bar connected to said presser foot for applying pressure thereto, and holddown means operatively disposed between said presser bar and said rear foot section for precluding movement of said rear foot section when said presser bar is operated to raise said front foot section, said rear foot section including a yielding section located in spaced relation on the underside thereof, and biasing means urging said yielding section downwardly from said rear foot section for engagement with a thread chain between sewing operations.

8. In a sewing machine, a presser foot having a plurality of sections including a front foot section and a rear foot section, a presser bar connected to said presser foot for applying pressure thereto, distributing means for distributing more of said pressure to said front foot section than to said rear foot section, a main feed dog having material-feeding teeth thereon facing in the direction of feed, and a differential feed dog having material-feeding teeth thereon facing opposite the direction of the teeth on said main feed dog; said main feed dog being located for cooperating with said rear foot section, said differential feed dog being located for cooperating with said front foot section.

9. In a sewing machine, a presser foot having a plurality of sections including a front foot section and a rear foot section, a presser bar connected to said presser foot for applying pressure thereto, holddown means operatively disposed between said presser bar and said rear foot section for precluding moVement of said rear foot section when said presser bar is operated to raise said front foot section, a main feed dog having material-feeding teeth thereon facing in the direction of feed, and a differential feed dog having material-feeding teeth thereon facing opposite the direction of the teeth on said main feed dog; said main feed dog being located for cooperating with said rear foot section, said differential feed dog being located for cooperating with said front foot section.

11. Apparatus as defined in claim 10 wherein said yielding section includes inturned lip means engaging a portion of said presser foot for retaining said yielding section with said slot means.

13. Apparatus as defined in claim 12 wherein the stepped rows of teeth on said main feed dog and said differential feed dog are in line with each other.

16. A method of producing a pucker-free seam when sewing woven materials comprising the steps of providing a main feed dog with material-feeding teeth thereon facing in the direction of material feed, providing a differential feed dog with material-feeding teeth thereon facing in the direction opposite from the direction of material feeding, and controlling the length of travel of said differential feed dog so it is shorter than the length of travel of said main feed dog.