US1984755A - Blind stitch sewing machine - Google Patents

Description

1934- c. w. MUELLER BLIND STITCH SEWING MACHINE Filed Feb. 24, 1952 5 Sheets-Sheet 1 INVENTOR C M/[fueller ATTORNEY Dec. 18, 1934 c w MUELLER I 1,984,755

BLIND STITCH SEWING MACHINE Filed Feb. 24, 1952 3 Sheets-Sheet 2 Dec. 18, 1934. c. w. MUELLER BLIND STITCH SEWING MACHINE Filed Feb. 24, 1932 I5 Sheets-Sheet 5 ulllllllllllllljlgln In w Patented Dec. 18, 1934 UNITED STATES 1,984,755 BLIND STITCH SEWING MACHINE Charles W. Mueller, St. Louis, Mo., assignor to Lewis Invisible Stitch Machine Company, St. Louis, Mo., a corporation of Maine Application February 24, 1932, Serial No. 594,930 I 15 Claims. (Cl. 112-178) This invention relates to new and useful improvements in blind'stitch sewing machines generally, although more particularly to machines for blind stitching hems along the bottoms of skirts and on other articles of wearing apparel, and embodies certain improvements and changes over my co-pending application Serial No. '75,- 891, filed November 18, 1931, which discloses a flat bed type of machine such as is shown in my prior Patent 1,764,573, June 17, 1930.

The present invention is shown as applied to a cylinder or work arm type of machine such as is illustrated in my prior Patents 1,539,399, May 26, 1925 and 1,791,220, February 3, 1931,

Among the several objects of my invention are,

to provide in a blind stitch sewing machine, a presser foot having a slot ending rearwardly from the front edge thereof, and through which the hem fold is projected upwardly into needle penetrating position, and a hemmer mounted in front of the foot with its nose located directly in front of the slot whereby the length of the hem fold between the needle and the nose of the folder will be reduced to a minimum and the hem will be caught by the needle before it can possibly unfold; to provide such a hemmer which can be easily adjusted laterally, vertically, and also back and forth, relative to the stationary presser foot whereby the nose of the hemmer may be properly positioned relativ'eto the point of needle penetration regardless of the weight of material being. hemmed; to provide a bottom and top feedingmeans for insuring the proper feeding action to the hemmed material, and to support the hemmer on a flat work plate which is mounted on the machine frame for vertical movements and also for back and forth movements.

With these and other objects in view which will more fully appear, the nature of the invention will be more clearly understood ,by following the description, the appended claims, and the several views illustrated in the accompanying drawings.

In the drawings:

Figure 1 is a front elevation of a sewing machine embodying my invention. I

Figure 2 is a left hand elevation thereof.-

Figure 3 is a horizontal sectional view taken directly above the stationary presser foot and showing particularly the relation between the hemmer and the foot and the means forsupporting the hemmer on the work support, as well as the means for mounting the work support on the standard.

Figure 4 is a vertical longitudinal sectional view thereof.

Figure 5 is an enlarged top plan view of the work'pressing mechanism which is disposed directly below the presser foot.

Figure 6 isan enlarged detailed horizontal view'showing particularly the relation between the stationarytpresser foot and the hemmer.

Figure 7 is a bottom plan view of the foot.

Figure 8 is a' perspective view of the main feed dog,

Figure 9 is'a perspective view of the'auxiliary spring pressed feed dog, and

Figure 10 is a vertical section taken through the feed dog.

Referring to the drawings, my invention is disclosed as being illustrated in the blind stitch sewing machine of the well-known Lewis type, and includes a base A, a post or standard B, an overhanging arm C which supports at its outer end a stitching head D, and a work arm E which projects laterally from the standard B and terminates at its free end under the stitching head D.

Rigidly attached to the lower end of the stitching headjD is a presser foot 5. Thefront right hand corner portion of the foot is cut away as at 6 which forms a resultant transverse front wall or edge '7. The foot is provided centrally with a slot 8 which extends rearwardly from the front edge 7. The presser foot is also provided in rear of the slot 8 with a top feed slot '9, and at the left of the slot 8 with alooper clearance slot 10. 7

As previously stated my invention is adapted to form a hem fold in a fabric and blind stitch said hem fold. In the present instance I have disclosed a single thread stitch forming mechanism for blind stitching the hem, but I wish it tobe understood that any other stitch forming mechanism may be employed if desired. In the present instance'a single thread stitch forming mechanism includes a curved needle 11 which is fixed to an oscillatory needle arm 12 which is driven from the main shaft 13, journaled in the overhanging arm C through'th'e medium of driving connections'indicated as a whole by the reference numeral 14. The needle llhas its penetratingmovement across the line of the feed of the material and in aplane directly above the slot 8' of the foot. Cooperating with the needle 11 to form a line of single thread chain stitches is a looper 15 Which'is rnounted on the stitching head D and has itsmovements imparted thereto from the 'main shaft 13 through the medium of driving connections indicated as a whole by the reference numeral 16, the looper during each cycle being received by the looper clearance slot 10.

Disposed above the work arm E and pivotally and detachably supported on the standard A is a flat work plate 1'7. The right hand end of the plate 17 is provided with front and rear and downwardly extending legs 18, l9 which embrace the standard A. Pivot screws 20, 21 are threadably engaged in the legs 18, 19 and the inner ends of these screws are pivotally mounted in bearing seats 22, 23 respectively formed in the front and rear faces of the standard A. Clamping nuts 24, 25 are respectively associated with the pivot screws and co-operate with the legs to retain the screws in adjusted positions. The work plate 17 extends to the left of thepresser foot 5 and is provided with an opening 26 directly thereunder, said opening extending forwardly from the rear edge of the plate. Rigidly connected to the upper face of the work arm E is an anchor or post 27. Preferably this post comprises a threaded shank which has threaded engagement in an opening 28 formed in the work arm E, and the upper end of the shank is provided with a head 29. A clamping nut 30 has threaded engagement with the shank and cooperates with the arm E to clamp the post rigid ly to the arm in different positions of vertical adjustment. Formed in the work plate 17 at one side of the post 27 is a threaded opening 31, and engaged in this opening for vertical adjustments is an adjusting post 32 which projects downwardly below the lower face of the work plate 1'? and is provided on its projectingend with a peripheral groove 33 for receiving the head 29 of the rigid post 2'7. The adjusting post 32 projects above the work plate 17 and fixed to the upper end thereof is a knurled head 34. Cooperating with the knurled head 34 is a spring detent 35 which is mounted on the work plate 17 and functions to retain the adjusting post 32 in different vertical positions. It will therefore be seen that by turning the adjusting post 32 the work plate 17 may be swung vertically about the pivot screws 20, 21 and that by means of the detent 35 the adjusting post 32 will be retained against accidental rotation and consequently the work plate 17 will be retained in a vertically adjusted position. It will also be observed that the work plate 17 may be adjusted forwardly or backwardly by loosening one of the pivot screws and tightening the other, this backward and forward movement being permitted by reason of the adjusting post 32 being disposed at one side of the anchoring post 2'7.

A hemmer 36 is rigidly mounted on the work plate 17 at a point in front of the presser foot 5, the nose of the hammer projecting rearwardly into the space formed by the cut out portion 6 of the foot and having its delivery end located directly in front of the slot 8 of said foot. The hemmer 36 is provided with a laterally extending supporting arm 37 which underlies an extension arm 38 and is detachably secured thereto by means of screws 39. The extension arm 38 is seated between the front and rear guide ribs 40, 40 integrally formed on the upper surface of the work plate 1'7 and located slightly to the right of the presser foot 5. A clamping screw 41 passes through an unthreaded opening formed in the extension arm 38 and has threaded engagement in the work plate 1'7. The opening in the arm 38 having a slightly larger diameter than the diameter of the clamping screw so as to permit said arm 38 together with the hammer 36 being laterally adjusted. The guide ribs 40, 4e are disposed in parallel planes extending at right angles to the longitudinal axis of the presser foot. Consequently the hemmer may be adjusted laterally relative to the slot 8 within the limits defined by the clamping screw 41 and the. opening in the extension arm 38 through which the screw passes.

Disposed below the presser foot 5 and co-opcrating therewith to feed the hemmed fabric rearwardly past the needle is a work pressing mechanism which includes a work clamp F, a 4- motion main feed dog G, a 4 motion auxiliary feed dog H and a vertically reciprocatory ridge forming element I. The 4-motion main feed dog G has itsup and down and backward and forward movements imparted to it from the main shaft 13 through the medium of connections which are indicated as a whole by the reference numeral 42, and which connections are disclosed in my prior Patent 1,791,220 referred to above, and further description thereof is thought to be unnecessary. In the present invention however the feed dog G is provided with. a supporting shank 43 to which a relatively long feed section 44 is integrally attached. This feed dog operates in a feed slot 45 formed in the work clamp F which is disposed at the left. of the ridge forming element I and extends from a point in front of the slot 8 of the presser foot we point in rear thereof. Thus the main feed dog section 44. engages the body of the fabric and feeds the same rearwardly from the hemmer 36 past the ridge forming element I. Rigidly connected to the shank 43 of the'main feed dog G adjacent the rear end thereof is a laterally extending arm 46. A vertical shank 47 isintegral with the right hand edge of the arm 46 and forms a resultant stop shoulder 48. The 4-motion auxiliary feed dog H is connected to the main feed dog G and co -operates directly with the hem fold. of the material to feed the hem and intermittently clamp said hem against the presser foot during the setting of the stitches to thereby prevent the hem from being curled or rolled. Furthermore this auxiliary feed dog H is yieldably mounted whereby hem folds of different thicknesses due to different weights of materials may be automatically accommodated. The auxiliary feed dog H includes a supporting bar and a relatively short and narrow feed section 51 which is integrally or otherwise fixedly secured to the bar. This bar is located above the arm 46 and below the stop shoulder 48, and the rear end of the bar is pivotally connected to the shank 47 by a horizontal pivot screw 52. The rear end of the feed section 51 is provided with a limiting stop 53 which is adapted to engage the stop shoulder 48 and thereby limit the upward movement of the auxiliary feed dog rela tive to the main feed dog. A coiled spring 54 has its upper end seated in a recess formed in the barc50 and the lower end of this spring rests upon the arm 45. Thus the spring 54 which is disposed in front of the pivot screw 52 yieldably retains the stop 53 against the stop shoulder 48. Thus the auxiliary feed section 51 yieldably engages the outer folded portion of the hem at the right of the line of needle penetrations and cooperates with the presser foot to clamp the hem therebetween, and thereby not only prevents the setting of the stitches from curling or rolling the hem, but also permits materials of different weights to be fed properly.

The work clamp F is caused to reciprocate vertically in timed relation with the main feed dog G, in the usual manner, whereby the work clamp is lowered during the feeding stroke of the feed dog and elevated, into clamping engagement with the presser foot during the return stroke of the feed dog in order to clamp the material against the penetrating stroke of the needle.

The ridge forming element I is in the form of a plunger which is reciprocated vertically in timed relation to the needle and to the main feed dog in the usual manner, whereby the plunger will be at the lower end of its stroke during the feeding motion of the feed dog and will be elevated during the idle portion of the feed movement to project a ridge of hemmed material upwardly through the slot 8-of the presser foot into needle penetrating position, whereby the needle will enter the body fabric and the inner edge of the hem as will be readily understood.

Co-operating with the lower feeds G and H to feed the hemmed material rearwardly is a 4- motion top feed dog J which operates in the top feed slot 9 of the presser foot. This top feed dog is mounted on the lower end of a lever 55 and has a sliding pivotal connection intermediate its ends in a guide 56 which is journaled in a horizontal bearing 57 fixed to the stitching head D. The upper end of the lever 55 engages an eccentric 58 fixed to the main shaft 13. Consequently, during each rotation of the main shaft the top feed lever 55 is oscillated about the horizontal bearing 57 and is also raised and lowered by reason of the lever sliding longitudinally through the guide 56, the component of these 4-motions producing a substantially elliptical path of travel.

From the foregoing it will be observed that I have provided a blind stitch sewing machine for stitching a hem fold along the edge of a fabric; that by reason of the front right hand corner of the presser foot being cut away the nose of the folder can be placed directly in front of the rearwardly extending slot 8 in the foot through which the ridge of hemmed material is upwardly projected into the path of needle penetration; that the hemmer is capableof being adjusted laterally relative to theslot 8, and also adjusted vertically as well as backwardly and forwardly relatively to the foot; that the folder is mounted upon a work plate which in turn is mounted on the frame of the machine for vertical adjustments and also for backward and forward adjustments; that the lower feed mechanism includes a vertically yieldable auxiliary feed dog which co-operates with the hem fold of the material to feed the same rearwardly regardless of the weight of the material being employed, and that a top feed mechanism co-operates with the lower feed mechanism to feed the hem fold rearwardly.

I claim:-

1. In a blind stitch sewing machine, the combination with a stationary presser foot having a slot extending rearwardly from the front end thereof, of a feeding means co-operating with the foot to feed the material rearwardly, a stitch forming mechanism including a reciprocatory needle disposed above the slot in the foot, a hemmer located in front of the foot and having its nose directly in front of the slot in saidfoot, a ridge forming element for projecting a ridge of hemmed material upwardly through the slot in the foot and into the path of the needle, and means for supporting the hemmer for backward and forward adjustments relative to said slot.

2. In a blind stitch sewing machine, the comits nose directly in front of the slot in said foot,

a ridge forming element for projecting a ridge of hemmed material upwardly through the slot in the foot and into the path of the needle, and means for supporting the hemmer for vertical adjustments relative to the foot.

3; In a blind stitch sewing machine, the combination with a stationary presser foot having a slot extending rearwardly from the front end thereof, of a feeding means co-operating with the foot to feed the material rearwardly, a stitch forming mechanism including a reciprocatory needle disposed above the slot in the foot, a hemmer located in front of the foot and having its nose directly in front of the slot in said foot, a ridge forming element for projecting a ridge of hemmed material upwardly through the slot in the foot and into the path of the needle, and means for supporting the hemmer for backward and forward adjustments relative to said slot and for vertical adjustments relative to the foot.

4; In a blind stitch sewing machine, the combination with a stationary presser foot having a slot extending rearwardly from the front end thereof, of a feeding means co-operating with the foot to feed the material rearwardly, a stitch forming mechanism including a reciprocatory needle disposed above the slot in the foot, a hemmer located in front of the foot and having itsnose directly in front of the slot in said foot, a ridge forming element for projecting a ridge of hemmed material upwardly'through the slot in the foot and into the path of the needle, and means for. supporting the hemmer for lateral adjustments relative to'said slot. v

5. In a blind stitch sewing machine, the combination with a stationary presser foot having a slot extending rearwardly from the front end thereof, of a'feedingmeans co-operat'ingwith the foot to feed the material rearwardly, a stitch forming mechanism including a reciprocatory' needle disposed above the slot in the foot, ahemmer located in front of the foot and having its nose directly in front of the slot in said foot, a ridge forming element for projecting a ridge. of hemmed material upwardly through the slot in..the foot and into the path of the needle, and means for supporting the hemmer for backward and forward and lateral adjustments relative to said slot.

6. ma blind stitch sewing machine, the combination with a stationary presser foot having a slot extending. rearwardly from the front end thereof, of a feeding means co-operating with the foot to feed the material rearwardly, a stitch forming mechanism including a reciprocatory needle disposed above the slot in the foot, a hemmer located in front of the foot and havingits nose. directly in front of the slot in said foot, a ridge forming element for projecting a ridge of hemmed'material upwardly throughthe slot "in the foot and into the path of the needle,

and means for supporting the hemmer for backward and forward and lateral adjustments relative to said slot and for vertical adjustments relative to the foot.

7. In a blind sitch sewing machine, the combination with a frame including a standard, an overhanging arm extending therefrom, a stitching head carried by the outer end of said arm, and a work arm extending from the standard and having its free end terminating under the stitching head; of a stationary presser foot fixed to the stitching head and provided with a rearwardly extending slot; a feeding means co-opcrating with the foot to feed the material rearwardly; a stitch forming mechanism including a reciprocatory needle disposed above the slot in the foot; a work plate disposed above the work arm; a hemmer mounted on the work plate in front of the foot and having its nose located directly in front of the slot in the presser foot; and a ridge forming element mounted on the work arm for projecting a ridge of hemmed material upwardly through the slot in the foot and into the path of the needle.

8. In a blind stitch sewing machine, the combination with a frame including a standard, an overhanging arm extending therefrom, a stitching head carried by the outer end of said arm, and a work arm extending from the standard and having its free end terminating under the stitching head; of a stationary presser foot fixed to the stitching head and provided with a rearwardly extending slot; a feeding means cooperating with the foot to feed the material rearwardly; a stitch forming mechanism including a reciprocatory needle disposed above the slot in the foot; a work plate disposed above the work arm; a hemmer mounted on the work plate in front of the foot and having its nose located directly in front of the slot in the presser foot; a ridge forming element mounted on the work arm for projecting a ridge of hemmed material upwardly through the slot in the foot and into the path of the needle; and means for supporting the work plate on the frame for backward and forward adjustments.

9. In a blind stitch sewing machine, the combination with a frame including a standard, an overhanging arm extending therefrom, a stitching head carried by the outer endof said arm, and a work arm extending from the standard and having its free end terminating under the stitching head; of a stationary presser foot fixed to the stitching head and provided with a rearwardly extending slot; a feeding means cooperating with the foot to feed the material rearwardly; a stitch forming mechanism including a reciprocatory needle disposed above the slot in the foot; a work plate disposed above the work arm; a hemmer mounted on the work plate in front of the foot andhaving its nose located directly in front of the slot in the presser foot; a ridge forming element mounted on the work arm for projecting a ridge of hemmed material upwardly through the slot in the foot and into the path of the needle; and means for supporting the work plate on the frame for vertical adjustments.

10. In a blind stitch sewing machine, the combination with a frame including a standard, an overhanging arm extending therefrom, a stitching head carried by the outer end of said arm, and a work arm extending from the standard and having its free end terminating under the stitching head; of astationary presser foot fixed toxthe stitching head and provided'with' a rearwardly extending slot; a feeding meanscooperating with the foot to feed the material rearwardly; a stitch forming mechanism including a reciprocatory needle disposed above the slot in the foot; a work plate disposed above the work arm; a hemmer mounted on the work plate in front of the foot andhaving its nose located directly in front of the slot in the presser foot; a ridgeforming'element mounted on the work arm for projecting a ridge of hemmed material upwardly through the slot in the foot and into the path of the needle; and means for supporting the work plate on the frame for backward and forward and vertical adjustments.

11. In a blind stitch sewing machine, the combination with a frame including a standard, an overhanging arm extending therefrom, a stitching head carried by the outer end of said arm, and a work arm extending from the standard and having its free end terminating under the stitching head; of a stationary presser foot fixed to the stitching head and provided with a rearwardly extending slot; a feeding means rcooperating with the foot to feed the material rearwardly; a stitch forming mechanism including a reciprecatory needle disposed above the slot in the foot; a work plate disposed above the work arm; a hemmer mounted for lateral adjustments on the work plate in front of the foot and having its nose located directly in front of the slot in the presser foot; a ridge forming element mounted on the work arm for projecting a ridge of hemmed material upwardly through the slot in the foot and into the path of the needle; and means for supporting the work plate on the frame for backward and forward adjustments.

12. In a blind stitch sewing machine, the combination with a frame including a standard, an overhanging arm extending therefrom, a stitching head carried by the outer end of said arm, and a work arm extending from the standard and having its free end terminating under the stitching head; of a stationary presser foot fixed to the stitching head and provided with a rearwardly extending slot; a feeding means cooperating with the foot to feed the material rearwardly; a stitch forming mechanism including a reciprocatory needle disposed above the slot in the foot; a work plate disposed above the work arm; a hemmer mounted on the work plate in front of the foot and having its nose located directly in front of the slot in the presser foot; a ridge forming element mounted on the work arm for projecting a ridge of hemmed material upwardly through the slot in the foot and into the path of the needle; horizontal pivots supporting the end of the work plate opposite the presser foot on the standard; and means connecting the work plate and work arm for vertically adjusting the plate relative to the presser foot and the work arm.

13. In a blind stitch sewing machine, the combination with a frame including a standard, an overhanging arm extending therefrom, a stitching head carried by the outer end of said arm, and a work arm extending from the standard and having its free end terminating under the stitching head; of a stationary presser foot fixed to the stitching head and provided with a rearwardly extending slot; a feeding means co-operating with the foot to feed the material rearwardly; a stitch forming mechanism including a reciprocatory needle disposed above the slot in the fcot; a work plate disposed above the work arm; a hemmer mounted on the work plate in front of the foot and having its nose located directly in front of the slot in the presser foot; a ridge forming element mounted on the work arm for projecting a ridge of hemmed material upwardly through the slot in the foot and into the path of the needle; horizontal pivots supporting the end of the work plate opposite the presser foot on the. standard; and means connecting the Work plate and work arm for vertically adjusting the plate relative to the presser foot and the work arm, said connecting means including a headed anchor post disposed under the work plate and secured to the work arm, and a 'vertically adjustable post mounted on the work plate and having a peripheral groove on its lower end engageable with the head of the anchor post.

14. In a blind stitch sewing machine, the combination with a frame including a standard, an overhanging arm extending therefrom, a stitching head carried by the outer end of saidarm, and a work arm extending from the standard and having its free'end terminating under the stitching head; of a stationary presser foot fixed to the stitching head and provided with a rearwardly extending slot; a feeding means co-operating with the foot to feed the material rearwardly; a stitch forming mechanism including a reciprocatory needle disposed above the slot in the foot; a work plate disposed above the work arm; a hemmer mounted on the work plate in front of the foot and having its nose located directly in front of the slot in the presser foot; a ridge forming element mounted on the work arm for projecting a ridge of hemmed material upwardly through the slot in the foot and into the path of the needle; horizontal pivots supporting the end of the work plate opposite the presser foot on the standard; and means connecting the work plate and work arm for vertically adjusting the plate relative to the presser foot and the work arm, said connecting means including a headed anchor post disposed under the work plate and secured to the work arm, and a vertically adjustable post mounted on the work plate and having a peripheral groove on its lower end engageable with the head of the anchor post, the work plate being bodily adjustable forwardly and rearwardly at its pivots, and the anchor post being at one side of the adjusting post.

15. In a blind stitch sewing machine, the combination with a stationary presser foot having a slot extending rearwardly from the front end thereof, of a lower feeding means co-operating with the foot to feed the material rearwardly, a stitch forming mechanism including a reciprocatory needle disposed above the slot in the foot, a hemmer located in front of the foot and having its nose directly in front of the slot in said foot, and a ridge forming element for projecting a ridge of hemmed material upwardly through the slot in the foot and into the path of the needle, said feeding means including a i-motion feed dog engageable with the fabric adjacent the hem and a vertically yieldable 4-motion auxiliary feed dog engageable with the hem.

CHARLES W. MUELLER.

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