US2768685A

US2768685A - Pinking attachment for sewing machines

Info

Publication number: US2768685A
Application number: US186585A
Authority: US
Inventors: Herbert F Sharar
Original assignee: Individual
Current assignee: Individual
Priority date: 1950-09-25
Filing date: 1950-09-25
Publication date: 1956-10-30
Anticipated expiration: 1973-10-30

Description

Oct. 30, 1956 H. F. SHARAR 2,768,685

PINKING ATTACHMENT FOR SEWING MACHINES Filed Sept. 25, 1950 2 Sheets-She6t 1 83 I y 1 ill/2;. 6 M V INVENTOR l 4 4 .40 Herber/ SAG/13f Y M w ATTORNEY 0d. 30, 1956 H. F. SHARAR 2,768,685

PINKINGATTACHMENT FOR SEWING MACHINES Filed Sept. 25, 1950 2 Sheets-Sheet 2 l N VE NTOR 7 Herer/ K 36mm 477. BY mQm TTORNEY United States PINKING ATTACHMENT FOR. SEWING MACHINES This invention relates to an improvement in pinking attachr'nent's for sewing machines and deals particularly with a device which may be producedat low cost and which is adaptable to fit most sewing machine's;

Various types of pinking devices have been produced which may be attached to a sewing machine'and which may be operated to pink the edges of fabric. Most of these devices are rather complicated in c'onstructionan'd are accordingly high in cost. Furthermore, most such attachments are designed to fit only a particular brand of sewing machine. As a result'a somewhat different form of construction must be employed'for each sewing machine so that it may be properly attached thereto.

An object of the present invention resides in the provision of a pinking attachment which may be applied'to virtually any standard sewing machine, either of the household type or of the factory or commercial type without dismantling orchanging' parts of the machine and without the application of screws, nuts, bolts, .or other :similar means. In the present structure a portion of the attachment extends beneath the presserfoot of the sewing machine and is held in position thereby. Suitable means on the attachment engage against the presser foot to hold :the apparatus properly aligned.

A feature of the present invention lies in the provision of apinking attachment which includesja generally tubular housing having a split or slit alon'gone vertical Wall thereof through which the fabric to be pinked may extend. The bottom portion of the housing beneath the slit serves to contain a rotatable anvil against which the cutting wheel may cut. The upper portion of the housing acts to support a shaft rotatably mounting the cutting wheel. The housing is formed of resilient material which holds the cutter wheel against the rotatable anvil and compensates for variation due to wear. This resilient contact between the cutter wheel and the rotatable anvil maintains proper tensional force for efficient operation and eliminates the conventional types of pressure springs usually necessary to hold the cutter wheel against the anvil.

feature of the present invention lies in the provision 'of a housing formed of sheet: metal die stamped into generally tubular form with a split in one wall of the tube, the portion of the housing below the split serving to detachably support the frame on which the anvil is mounted and to detachably support the feed bedwhich is preferably integral with the anvil supporting frame. This permits the anvil frame to be quickly and economically formed of sheet material so as to maintain a low cost of production. The feed bed is elevated above the feed table of the sewing machine and is bent downwardly at its forward end to facilitate the feeding of the work to the pinker. v

A feature of the present invention resides in the sim plicity of the construction. The housing is die stamped froma single strip of material and servesj toresiliently support the cutter wheel and theclutch mechanismfor actuating the cutter wheel. The feed'bed and frame for supp'otting the rotatable anvil may be easily produced so that the frame will readily fit within the lower portion of the housing. A single screw may hold the two main parts assembled, thus producing a structure which may be manufactured at low cost. The axis of the rotatable an vil is off-set from a vertical plane through the axis of the cutter wheel. As a result the cutter wheel engages the anvil at a point slightly spaced from the lowest portion of the cutter wheel. The single screw connecting the twomain parts of the body may thus serve to adjust the pressure of the cutting wheel against the anvil by moving the axis of the anvil toward or away from a vertical plane. through the axis of the cutter wheel.

A feature of the present invention lies in the provision of a'clutch unit which is supported on the shaft of the cutter wheel inwardly of the housing. An arm extends from the housing which is engageable with the vertically reciprocable needle support of the sewing machine. Thus as the needle support reciprocates vertically, the arm acts through the clutch unit to advance the cutter wheel.

A feature of the present invention resides in the provision of a novel clutch unit which eliminates the conventional pivot pawl and spring. The ratchet dog of the present structure comprises a wedge shaped element which is designed to engage against the ratchet wheel to operate the same as the dog is moved in one direction and which slides over the ratchet wheel as the dog moves in the opposite direction. The construction is such that no springs or other such parts are necessary to advance the ratchet. As a result the clutch construction is extremely low in cost and' is easily assembled.

An additional feature of the present invention lies in theprovision' of a guide which serves to properly locate the stitching of a seam relative to the line along which the work is pinked. This guide is designed to overlie the stitching of the seam. By maintaining the stitching beneath the indicator, the work is pinked at a predetermined distance from the stitching. This is of particular importance in pinking the edges of curved or uneven materials and insures a seam edge of sufficient width to prevent the seam from pulling out.

These and other objects and novel features of my invention' will be more clearly and fully set forth in the following specification and claims.

In the drawings forming a part of my specification:

Figure 1 is a side elevational view of the pinking attachment' showing in general the construction thereof.

Fi'g11re2 is an end elevation view of the same.

Figure 3 is a top plan view of the pinking attachment showing the device in operation.

Figure 4 is a perspective view of the apparatus showing the anchoring plate used for holding the pinking attachment in place.

Figure 5 is a perspective view of the pinking attachment' feed bed in inverted position to show the construction thereof.

Figure 6 is a sectional view through a portion of the pinking attachment adjacent to the clutch, the position of thesection being indicated by the line 66 of Figure 2.

. Figure 7 is an elevation view of a modified form of housing construction showing a simplified type of scam width indicator.

The pinking attachment is indicated in general by the letter A. This attachment is designed for support upon the clutch plate 10 or feed table of a conventional sewing machine B. The sewing machine B is shown as including a hollow sewingmachine head 11 which supports the presser bar 12. The presser bar 12 is normally urged downwardly against the clutch plate It) by an internal springarrangement not illustrated in the drawings, but forming a part of a conventional sewing machinel The presser bar 12 supports at its lower end a presser foot 13 which is usually slotted longitudinally to accommodate the needle of the sewing machine. The presser foot 13 is provided with a socket 14 at its upper extremity which accommodates the lower end of the presser bar and is secured thereto by a set screw 15 or other suitable means.

The hollow head 11 of the sewing machine B also slidably supports the needle bar 16 which is provided near its lower extremity with a needle clamp 17. This needle clamp 17 normally includes a laterally projecting boss through which the set screw may extend for securing the needle in place. The needle bar 16 is normally reciprocated vertically by suitable mechanism within the body of the sewing machine, the needle 19 being movable through the slotted presser bar 13.

All of the foregoing construction is common to sewing machines of the conventional type and vary only in specific detail.

The pinking attachment A includes a housing which is probably best illustrated in Figure 4 of the drawings. This housing is indicated in general by the numeral 20 and includes a vertical panel 21 formed of sheet metal or other suitable material having inherent resilience. The wall panel 21 is connected at its upper extremity to a top wall 22 which in the particular form of construction illustrated is rounded. A wall flange or panel 23 is connected to the top panel 22 and extends downwardly parallel to the wall panel 21.

The wall panel 21 is also connected at its lower edge to a bottom panel 24 which in turn is connected to an upwardly extending flange or panel 25 which is generally parallel to the wall 21 and which is preferably aligned with the flange or panel 23. Thus a generally tubular housing is formed having a split 26 in one wall thereof.

A housing flange 27 is connected to the panel 25 to extend to or toward the wall panel 21. This flange 27 is preferably apertured at 29 near its center portion to accommodate a fastening and adjusting screw which will be later described. The rear of the housing is preferably open to simplify the assembly of the apparatus.

An anchoring plate 30 is connected to the edge of the bottom panel 24 adjacent the flange 27. This anchoring plate 30 is preferably provided with a marginal edge portion 31 which is on a common plane. A rectangular portion of the anchoring plate is off-set upwardly as indicated at 32 above the level of the marginal edge portion 31. A generally rectangular area 33 is recessed downwardly within this rectangular raised area 32, the recessed portion 33 being of proper size to accommodate the lower portion of the presser foot 13. The recessed portion 33 is slotted at 34 so that the needle of the sewing machine may pass through the anchoring plate and need not be removed during operation of the pinking attachment.

The feed bed assembly 35 is best illustrated in Figure of the drawings. This assembly is shown as including a generally flat feed bed or table 36 having a downwardly bent forward edge 37 which facilitates the feeding of the work to the pinking wheel. A flange 39 is bent downwardly from one edge 40 of the table 36. This flange 39 is connected along a generally right angular bend 41 to a flange 42 connecting the flange 39 with a parallel flange 43. The

flanges

39, 42 and 43 are thus generally U-shaped in plan and comprise a frame forsupporting the rotatable anvil. This rotatable anvil is indicated at 44 mounted on a shaft 45 which is supported by the

parallel flanges

39 and 43 of the frame thus produced. Suitable means may be provided for holding .the anvil from sliding axially along the shaft 45, the shaft being provided with shoulders or spacers of a suitable nature so as to rotatably support the anvil without permitting extensive axial movement thereof. 7

Theflange 42 of the anvil frame is apertured as indicated at 46, this aperture being preferably internally threaded. When the feed table assembly 35 shown in Figure 5 is assembled within the housing 20 and the elements supported by this housing, an adjusting screw 47 is designed to extend through the aperture 19 in the housing flange 27 and into the aperture 46 of the frame 42. By this means the frame flange 42 may be moved toward the flange 27 by tightening the adjusting screw 47.

A pivot shaft 49 is supported by the panel 21 and by the parallel panel 23 of the housing 20, and is grooved to accept a snap-on lock washer and knurled to hold the shaft from rotation relative to the housing. This shaft supports a clutch mechanism and cutting wheel assembly, best illustrated in Figure 2 of the drawings. As shown in this figure, an elongated hub 50 is rotatably supported upon the shaft 49. A pinking wheel or cutting wheel 51 of suitable shape to provide the proper pinking cut is mounted upon the hub 50 and may be keyed thereto if desired. The hub 50 is provided with a central enlargement 52 against which one side of the pinking wheel may bear. A threaded collar or nut 53 is threaded onto the end of the hub 50 to hold the pinking wheel firmly in place upon the hub.

A ratchet assembly is mounted on the other end of the hub 50. This ratchet assembly includes a pair of

discs

54 and 55 of relatively large diameter having a ratchet wheel 56 sandwiched therebetween. The ratchet wheel 56 is of small diameter relative to the discs 54 and '55 and may be keyed or otherwise fixed with respect to the hub 50. An internally threaded collar 57 or nut is threaded upon the hub 50 to clamp the

discs

54 and 55 and the ratchet wheel 56 against the enlarged diameter center portion 52 of the hub.

A ratchet operating arm 59, best illustrated in Figure 6 of the drawings, encircles the ratchet wheel 56 and is provided with an aperture 60 therethrough of proper diameter to accommodate the ratchet wheel. A generally triangular notch 61 is formed in the arm 59 in communication with the circular aperture 60. This triangular notch has an apex 62 spaced at a substantial distance from the periphery of the aperture 60 and includes diverging

side walls

63 and 64 which extend from the apex 62 toward the aperture 60. The edge 63 of the notch terminates in a substantially radially extending offset 65 while the edge 64 of the notch intercepts the aperture 62 at an angle slightly less than a tangent to the aperture 60.

A wedge shaped dog 66 is provided in the notch 61. This dog 66 has two diverging

edges

67 and 69 which are generally parallel to the

corresponding edges

63 and 64 of the notch 61. The third side of the generally triangular dog 66 is substantially arcuate throughout the major portion of its length so as to lie outwardly of the latch teeth at all times. However, at one end of this third side of the dog 66 I provide a tooth edge 70 which is properly shaped to extend into the ratchet wheel to engage successive teeth thereof. The ratchet dog is of dimensions sufiiciently less than the dimensions of the notch 61 to permit the tooth 70 to ride over the ratchet teeth during rotation of the arm 59 in a counter-clockwise direction as viewed in Figure 6. In such an event the ratchet dog slides toward the apex 62 of the notch 61. However, as the arm 59 is rotated in a clockwise direction as viewed in Figure 6, the dog will slide away from the apex 62 of the notch and the tooth 70 will engage against a tooth of the ratchet wheel 56 so as to rotate the ratchet wheel in conjunction with the arm 59.

A guide is provided on the housing wall panel 23 to assist in maintaining the pinking wheel at a constant distance from the stitching of a seam. In Figure 3 of the drawings I disclose two layers of fabric, or other work, 71. connected together along a row of stitching 72. It is desired to pink the material 71 outwardly of the stitching 72 so that the pinked edge is substantially an even distance from the stitching throughout the same. I providean indicator finger 73-pivotal1y supported at easiest p'iier'zsp' This finger 73 extends-into close pfoxirnity with the m'at'erial 71" being piiik'e'd. 1r thework is ffed into the' pinldng wheel in such a'way thatthe finger 731s at all times above the row of stitching 72; the seam edges 74 outwardly of the stitching 72'will be of substantially'constant Width.

It absolutely essential to provide a pivoted indica tor finger inorder to provide a proper guide. In Figure 7 of the drawing s I disclose a housing 75' which is: provided with a housing Wall panel 76 corresponding to the panel 23 of the previously described structure. This panel 76 is parallel to the housing wall 77 and so arranged as to support a pivot 79 upon which the cutting wheel may pivot. The panel 76 is provided with a downwardly extending projection 80 which extends down into close proximity with the work 71 being pinked. Thu-s by properly dimensioning the housing and properly locating the cutting wheel relative to the housing, the split wall: of the housing may serve as a guide, eliminating the necessity of the pivoted finger 73.

In the operation of the device, the attachment is placed upon the clutch plate 10 while the presser foot 13 is raised and the anchor plate is placed beneath the presser foot. The presser bar 12 is then lowered to clamp the presser foot against the anchoring plate 3?. As the depression 33 is of proper shape to accommodate the lowest portion of the presser foot, the attachment will be properly aligned with the machine. In place of the depression 33 various types of shoulders may be provided engageable with the presser foot to prevent twisting or moving of the anchoring plate. It will be noted that the depressed portion 33 does not extend to the level of the clutch plate 10 to avoid interference with the cloth advancing mechanism usually provided directly beneath the presser foot.

At the same time the anchoring plate 30 is moved beneath the presser foot, the slotted end 8]. of the arm 59 is engaged with the needle clamp 17 of the needle bar 16. This may be done in any position of the needle bar by either pivoting the arm 59 so that the slotted end 81 is at a proper elevation or by rotating the sewing machine mechanism until the needle bar 16 is at a proper elevation. When the presser foot is engaged with the anchoring plate the apparatus is in readiness for use. The work to be pinked is next merely fed over the feed plate 36, the material being fed from tie downwardly inclined forward edge 37 of the presser plate toward the other end thereof. It will be noted that the wall panel 21 is off-set from the needle bar 16 and presser bar 12 so that work may be directly fed through the housing without interference by any other part of the sewing machine. Furthermore, it will be noted that the pinking attachment is supported to the left and fo wardly of the needle bar and presser bar so that work of any dimensions may be pinked without passing the material through the arbor or frame of the sewing machine.

When the sewing machine is operated the vertical reciprocation of the needle bar 16 acts to oscillate the arm 59 about the axis of the pivot shaft 49. Each time the arm 59 is rotated in a clockwise direction, as viewed in Figures 1 and 6, the dog 66 engages the ratchet to rotate the pinking Wheel 51, thus pinking the material which passes between the pinking wheel and the rotatable anvil. During oscillation of the arm 59 in a counter clockwise direction, the pinking wheel remains stationary. It will be noted from Figure 1 of the drawings that the axis of the rotatable anvil 44 is slightly forwardly of a vertical plane through the axis of the pivot 49. As a result the anvil 44 engages the periphery of the cutting wheel slightly forwardly of the lowermost extremity thereof. As a result the upper extremity of the rotatable anvil 44 is slightly above the level of the lowest portion of the cutting wheel 51. This makes possible the adjustment of the pressure between the cutting Wheel 51 and the anvil 44 by moving the anvil axis 45 closer 6 to, or fa rther f ronithe vertical plane thr'oughthe axis of the pivot shaft '49I' By' rotating the adjusting screw 47' the framesupporting the rotatable anvil, as well as the feed table'36, maybe moved rearwardly, thereby increasing'the pressure between the anvil and the cutting wheel. If thescrew 47 is released slightly the frame mayrnove tojthe right as indicated in Figure 1, thereby decreasing the" tension between the cooperable rotatable elements. I V

The recess 33" is bounded'by inclined inwardly and downwardly tapering'walls so'that the recess may accommodate presser feet of different widths. The tapering walls center the p'ress'er foot with the slot 34' even though'the'p're'sser' fo'ot ca'n'not engage the bottom of the recess. This featurejis' of advantage'in' producing a construction whi'ch'will fit on sewing machines of various types. v

As indicated" in Figures 1'" and 2' of the drawings, a bearing 82 encircles the shaft 45 on which the anvil 44 is mounted so as to permit this anvil to rotate freely even when pressure isl exertedthereagainst. The bearing 82 may be ofa sleeve type, or may" be a roller or ball bearing; .7

The portions of the housing front may obviously be varied in shape; and by use of the words split and slit to define the continuous opening through the front casing Wall through which the material to be pinked is fed, I do not intend to confine myself to any particular shape of opening.

In accordance with the patent statutes, I have described the principles of construction and operation of my pinking attachment, and while I have endeavored to set forth the best embodiment thereof, I desire to have it understood that this is only illustrative thereof and that obvious changes may be made within the scope of the following claims without departing from the spirit of my invention.

I claim:

1. An attachment fora sewing machine having a presser foot, a needle bar, a clutch plate, and a cloth advancing mechanism beneath the presser foot, the attachment including an anchoring plate supported by said clutch plate and bridging said clutch advancing mechanism, said anchor plate including means engageable with edges of the sides of presser foot in lowered position thereof to prevent the anchor plate from lateral movement relative to the presser foot.

2. The structure described in claim 1 and in which the anchor plate is provided with an aperture therethrough through which the needle supported by the needle bar may extend.

3. A pinking attachment for sewing machines having a presser foot, a needle bar, a clutch plate, and mechanism beneath the presser foot for advancing cloth resting upon the clutch plate, the attachment including an anchor plate designed for support upon the clutch plate, said anchor plate being off-set to bridge said clutch advancing mechanism, abutment means on said anchor plate cooperable with the presser foot to hold the anchor plate in fixed position on the clutch plate in lowered position of the presser foot, a housing connected to said anchor plate, pinking means supported by said housing, and means connected to said housing and eng-ageable with the needle bar for rotating said pinking means.

4. The structure described in claim 3 and including clutch means connecting said last named means and said pinking means.

5. The structure described in claim 4 and in which the abutment cooperable means on the anchor plate comprises a recessed portion in said anchor plate designed to accommodate the presser foot.

67 The structure described in claim 4 and in which the abutment means on the anchor plate cooperable with the presser foot includes a recessed portion in the anchor plate having downwardly and inwardly sloping walls for accommodating presser feet of various sizes.

7. A pinking attachment for sewing machines including a housing, a pinking wheel rotatably supported by said housing means for rotating said pinking wheel, a rotatable anvil, a slidably supported frame for rotatably supporting said anvil, said pinking wheel normally engaging said anvil at a point spaced from the lowermost extremity of the pinking wheel, and cooperable means connecting said housing and said frame and sliding the axis of the anvil relative to the axis of the pinking'wheel, in a general horizontal direction to position the axis of the anvil more closely adjacent to a vertical plane through the axis of the pinking wheel and in which the housing comprises a resilient sheet metal body including a lower portion in which said anvil is located and an upper portion in which said pinking wheel is located, said upper and lower housing portions being connected by a single wall of said housing, the housing being sufficiently resilient to urge the cutting wheel under tension against said anvil.

References Cited in the file of this patent UNITED STATES PATENTS 283,001 Mason Aug. 14, 1883 8 Cummins et al. Nov. 27, 1894 Kosch Oct. 22, 1901 Sweet Feb. 13, 1906 Weinbach et a1 Jan. 25, 1910 Harriman June 25, 1918 Barron et a1. Aug. 9,,1921 Grieb July 7, 1925 Lappin Apr. 1, 1930 Peaker et al Apr. 26, 1932 Karle Mar. 27, 1934 Niukkanen Mar. 26, 1935 Kleiman et a1 Nov. 24, 1936 Spielman Oct. 26, 1937 Crewdson Ian. 11, 1938 Weis Dec. 27, 1938 Alifano et al. June 15, 1948 McMurray July 11, 1950 FOREIGN PATENTS Great Britain May 9, 1951