US2927547A

US2927547A - Buttonhole attachment for sewing machines

Info

Publication number: US2927547A
Application number: US720099A
Authority: US
Inventors: John P Enos
Original assignee: Singer Co
Current assignee: Singer Co
Priority date: 1958-03-10
Filing date: 1958-03-10
Publication date: 1960-03-08
Anticipated expiration: 1977-03-08
Also published as: FR1221994A; ES247787A1; DE1083108B; GB877527A; CH371332A

Description

March 8, J. P. ENOS BUTTONHOLE ATTACHMENT FOR SEWING MACHINES Filed March 10', 1958 2 Sheets-Sheet 1 Fig.l.

I25 4 I26 g 38 Fig 3 36 INVENTOR.

John R Enos ATTORNEY m 7. W N

March 8, 1960 J. P. ENOS 2,927,547 BUTTONHOLE ATTACHMENT FOR SEWING MACHINES Filed March 10, 1958 INVENTOR. John P. Enos TTORNEY Sttes BUTTONHOLE ATTACHNIENT FOR SEWING MACHINES Application March 10, 1958, Serial No. 720,099 8 Claims. (Cl. 112--77) This invention relates to buttonhole attachments for sewing machines, and more particularly, to a buttonhole attachment of the type in which the shape of. the buttonhole is dictated by a template.

it is an object of thisinvention to provide an improved buttonhole attachment in which the template may be re moved and replaced while the attachment remains operatively afiixed to the sewing machine.

Another object of this invention is to provide an improved compact buttonhole attachment construction which may be affixed conveniently to a sewing machine.

Still another object of this invention is to provide a buttonhole attachment adapted to be driven by a sewing machine and in which a minimum of effort is required to actuate the attachment.

With the above and other objects and advantages in view as will hereinafter appear, this invention comprises the devices, combinations, and arrangements of parts hereinafter described and illustrated in the accompanying drawings, in which:

Fig. 1 represents a top plan view of an attachment built in accordance with this invention with the cover removed, 7

Fig. 2 represents aleft elevational view of the attachment of Fig. l with the attachment cover illustrated in vertical cross section,

Fig. 3 is a horizontal cross-sectional view of the attachment taken substantially along the line 3-3 of Fig. 2,

Fig. 4 is a horizontal cross-sectional view of a portion of the attachment taken substantially along the line 4-4 of Fig. 2,

Fig. 5 is a horizontal cross-sectional view of the pattern cam actuating ratchet andpawl taken substantially along line 5-5 of Fig. 2,

Fig. 6 represents a right side elevational view of the attachment of Fig. 1 with the attachment cover illustrated in vertical cross section,

Fig. 7 is a vertical cross-sectional view taken substantially along line 77 of Fig. 6, and

Fig. 8 is a bottom view of a template adapted for use with the attachment of this invention.

Referring to the drawings, this attachment comprises a frame including a Hat base portion 11 at the forward extremity of which rises a block 12 formed with a seat 13 adapted to be received on the conventional depending presser bar of a sewing machine. The block 12 is apertured at 14 for a fastening screw so that the attachment frame may be secured to the sewing machine presser bar. The attachment frame block 12 is also formed with a pair of upstanding lugs 15 transversely of which is journaled a pivot stud 145 to which an attachment actuating bell crank 17 is made fast. The bell crank 17 is formed with bifurcated jaws 18 adapted to embrace the needle clamp on the needle bar when the attachment frame is secured on the presser bar. The endwise reciprocatory motion of the conventional needle bar thus serves to oscillate the bell crank 17, from which oscillatory motion'the work ate 2,927,547 Patented Mar. 8 196,0

upturned arms 25 which extend along opposite sides of the platform and serve to define a plane of support above and parallel to the platform plate 22 for the presser foot" shank of the attachment.

Indicated at 26 in the drawings is a work engaging presser foot formed with a keyhole-shaped aperture 27 occurs. The workv within which the buttonhole stitching engaging presser foot is pivoted on two spaced limbs 28 extending from the front portion of a presser foot. shank 29 which underlies the frame base portion 11. The front portion of the presser foot shank is formed witha lengthwise elongated aperture 3ii which slidably accommodates a headed fulcrum pin 31. The fulcrum pin passes upwardly through alengthwise elongated aperture 3 2 in the frame base 11 and is resiliently secured by means of a nut 33 and a beehive spring 34 to a bight adjusting angle bracket 35. The angle bracket 35 is provided with a stud 36 which-extends through a slot 37 in a raised side.-

wall 38 on the attachment frame base and the angle,

bracket is secured in selected position along the frame base aperture 32 by means of-a clamp nut 40 threaded on the stud 36. A pointer 41 extending from the angle bracket 35 and bent outwardly over the frame sidewali 33 serves to indicate the position of adjustment of the fulcrum pin 3?. relative to the frame. An arm 42, Fig. 4, extends rearwardly from the angle bracket 35 and into the guide slot defined between the finger 24 and the frame base lug 19 and serves to steady and thus to pre-v vent binding of the angle bracket.

The presser foot shank is formed with a rear portion 43 offset upwardly from the front portion 29 and joined thereto by means of a substantially vertical portion 44 which passes upwardly through a clearance aperture 45.

formed in the attachment frame base. The rear portion 42 of the presser foot shank is supported at each side by the upturned arms 25 of the platform plate 21.

The rear portionf iii of the presser foot shank is formed with an aperture 5t} and a pair of locating

holes

51 and 52 sized to accommodate an exchangeable template member 53 which may be inserted from the top of the attachment. The underside of the template member 53 is formed with an endles track slot 54 defining the shape of the buttonhole to be produced by the attachment and with an endless rack 55 corresponding in shape and surrounding the track slot. On the topside, the template member is formed with a plurality of outwardly extending ears 56 which engage the top surface of the rear portion of the presser foot shank to support the template member thereon.

Pins

57 and 58 formed to depend from the ears 56 enter the locating

holes

51 and 52, respectively, to position the template member accurately relatively to the presser foot shank. The pins and the corresponding locating holes may be made of different dimensions so that the template will be insertable in only one position in the presser foot shank which Will be particularly advantageous where an eyelet end buttonhole is being prepared in that the eyelet end will always occur at a predetermined extremity of the buttonhole tack. The aperture 50 in the presser foot shank is preferably made to accommodate the rack portion of the templateplate may be grasped readily for insertion into and removal from the attachment.

In Figs. 2, 6 and 7, an attachment cover 60 is illustrated. The cover preferably encases the entire top of the attachment frame with the exception of that portion of the block 12 which is formed with the presser bar accommodatlng seat 13. The cover is secured to the attachment frame by the

screws

61 and 62 and is provided with a lid 63 hinged at 64 to the cover and secured in closed position by a spring latch 65. The lid is preferably of such size as to expose, when opened, the template member 53 in any operative position of the template, thus to provide access to the template for replacement thereof at any time during the stitching of a buttonhole. Secured inside the lid 63 is a flat leaf spring 66 which, in the closed position of the lid, is disposed to bear downwardly against the template member 53 to prevent it from being accidentally raised relatively to the presser foot shank during operation of the attachment. The attachment cover 68 is formed with a vertical slot 67, illustrated in Fig. 6, through which passes the attachment actuating bell crank 17. The cover is also formed with indicia 68, Fig. 2, cooperating with the pointer 41 to indicate the position of the presser foot shank fulcrum pin with respect to the attachment frame.

The mechanism of the attachment for imparting motion to the presser foot 26 from the bell crank actuating lever 17 will now be described. Referring to Figs. 4, and 7, a bearing stud 70 formed with an annular shoulder 71 is fixed vertically on the flat base portion of the attachment frame by a screw 72. An oscillatory pawl carrying plate 73 is journaled on the periphery of the shoulder 71 and rests on the top of the base portion 11 of the attachment frame. Journaled on the stud 70 and resting upon the shoulder 71 is a ratchet wheel 74 on the hub of which is secured, as by a press fit, a face cam 75 formed with a cam groove 76. The cam and ratchet wheel are retained on the stud 70 by means of a screw 77 threaded axially into the stud. Carried on a pivot pin 78 on the pawl carrying plate 73 is a pawl 79 biased by a spring 80 into operative engagement with the ratchet wheel 74. A link 81 is pivoted to the pawl carrying plate by means of a pivot pin 82 and is also connected by a pivot pin 83 to the bellcrank 17. A leaf spring 84 secured to the underside of the platform plate 22 bears against the periphery of the face cam 75 to prevent retrograde movement thereof. The oscillatory movement of the bell crank 17, therefore, will be translated into stepby-stcp rotary motion of the face cam 75, the pawl 79 preferably being arranged to index one tooth of the ratchet wheel 74 on each cycle of needle reciprocation of the sewing machine.

The face cam groove 76, best illustrated in Fig. 4, is of regular sinuous conformation with the same number of lobes as there are teeth in the ratchet wheel 74. Since the lobes alternately extend outwardly and inwardly toward the center of rotation of the cam, the cam is thus capable of shifting a follower in opposite directions on alternate stitches of a sewing machine.

Referring particularly to Figs. 4 and 7, the cam groove 76 is tracked by a roller follower 96 journaled on the lower extremity of a stud shaft 91 and retained thereon by a headed screw 92. The shaft 91 is fixed in a slide plate 93 which rests upon the platform 22, and a shoulder 94 formed on the shaft 91 overlies the platform plate to locate the shaft 91 endwise thereon.

The platform plate 22 is formed with two parallel and preferably aligned

elongated apertures

95 and 96 extending transversely of the attachment frame. Shouldered guide screws 97 are threaded into the slide plate 93 and depend through the

elongated apertures

95 and 96. Rollers 98 journaled on the shouldered guide screws as best illustrated in Fig. 7, engage the sidewalls of the

apertures

95 and 96, thereby to guide the slide plate for movement transversely of the attachment frame with a minimum of frictional resistance. The aperture 96 is elongated sufficiently to provide clearance for the stud shaft 91. A projection 99 of the slide plate toward the rear of the attachment carries a pin 100 depending through a clearance aperture 101 formed in the platform plate 22. The pin is formed with an enlarged head which bears against the undersurface of the platform plate to prevent tipping of the slide plate.

The shaft 91 at its upper extremity enters snugly the track slot 54 in the template member 53. Bodily movement of the shaft 91 transversely of the attachment frame in response to the movement of the face cam will, therefore, oscillate the presser foot shank in opposite directions on successive stitches to jog the presser foot back and forth transversely of the attachment frame. Oscillation of the presser' foot shank will occur about the axis of the fulcrum pin 31 and, therefore, the magnitude of presser foot jogging movement may be adjustable by shifting the fulcrum pin between the extremes of adjustment by means of the clamp nut 40 and the stud 36.

Loosely journaled on the shaft 91 above the shoulder 94 thereon is a ratchet wheel surmounted by a pinion 111 fixed to the ratchet wheel. The pinion is disposed in mesh with the teeth of the endless rack 55 of the template member 53. As best illustrated in Fig. 3, a pawl 112 pivoted on the pivot pin 113 threaded into the plat form plate 22 is biased by a spring 114 into engagement with the teeth of the ratchet wheel 110 and serves to impart step-by-step rotary motion in one direction to the ratchet wheel as the ratchet wheel is bodily shifted with respect to the pawl by the action of the face cam on the stud shaft 91. A leaf spring 115 fixed to the projection 99 of the slide plate overlies and bears against the ratchet wheel to prevent retrograde turning movement thereof. This gradual turning movement of the ratchet wheel 110, and with it the pinion 111, causes the pinion to track the endless pattern rack 55, thus to shift the oscillating presser foot in a closed path as dictated by the template member 53. The combination of the lateral jogging motion of the presser foot and the motion in a closed path defines a buttonhole-shaped tack of stitches when applied to a work fabric held by the presser foot beneath the sewing machine needle.

As an aid in properly orienting a buttonhole tack on a garment, it is desirable that the operator have provision for rapidly positioning the pinion 111 in a particular part of the endless rack usually at one extremity thereof. For this purpose, a lever is journaled on the shoulder 94 of the shaft 91 and formed with an operator-influenced arm 121 extending outwardly beyond the attachment frame. Pivoted to the lever 120 on a pin 122 is a pawl 123 biased by a spring 124 into engagement with the ratchet wheel 110. A finger 125 extending from the lever 120 engages a coil spring 126 anchored on a pin 127 fixed inthe lug 15 of the attachment frame. The spring 126 serves to bias the lever 120 into the position illustrated in Fig. 3 in which the arm 121 bears against a stop lug 128 struck up from a rearward projection 129 of the slide plate. Turning of the lever 120, therefore, indexes the ratchet wheel 110 and the pinion 111 independently of the operation derived from oscillation of the bell crank 17 and thus, while the sewing machine is stopped, the operator may adjust the attachment into a particular correlation of the pinion with the rack of the template.

Referring particularly to Figs. 1, 3 and 6, the attachment is provided with an antifiagging device comprising a finger disposed rearwardly of the stitching point and adapted to bear downwardly against the work during descent of the needle to prevent the work from raising, or flagging as it is referred to in the art, with the needle. The finger 140 projects forwardly and downwardly from a vertical plate 141 which is bifurcated, as at 142, and embraces an annular groove 143 formed in the pivot stud 16. A headed screw 144 secured in the frame base portion 11 passes'through an aperture in the finger 140 and a coil spring 145 constrained between the finger and the head of the screw 144 serves to bias the finger 140 downwardly. An arm 146 extending from the finger 140 toward the rear of the attachment bears against a down-turned lug 147 formed on the platform plate 22 to steady the antifiagging device and to prevent sidewise motion thereof. One of the bifurcations 142 of the vertical plate 141 is formed with an outwardly offset follower-lug 148 disposed to overlie the bell crank lever 17 which is formed with a cam portion 149 arranged to lift the follower-lug and hence the entire antifiagging device after the needle has ascended out of the work. The finger 120 will thus be lifted away from the work when jogging or lengthwise motion of the presser foot occurs but will be biased into engagement with the work during needle penetration and needle withdrawal to prevent flagging. This construction provides a one-piece antifiagging device which partakes of purely reciprocatory, i.e. straight line, motion so that the antiflagging finger cannot impart any jogging motion to the work fabrics.

Having thus described the nature of the invention, what I claim herein is:

1. A buttonhole attachment for a sewing machine comprising an attachment frame adapted to be fixedly secured to said sewing machine, a work shifting member slidably pivoted to said attachment frame, a portion of said work shifting member being formed to overhang in spaced relation above said attachment frame, a cam member journaled for turning movement on said attachment frame in the space between said frame and the overhanging portion of said work shifting member, means carried by said attachment frame and adapted to be actuated by said sewing machine for imparting turning movement to said cam member, a cam follower member disposed to track said cam member, means on said attachment frame for supporting said cam follower member between the overhanging portion of said work shifting member and said attachment frame for bodily movement transversely of said attachment frame in response to movement of said cam member, a pinion rotatably journaled on said cam follower member, means carried on said attachment frame and operatively associated with said pinion to impart turning movement to said pinion in response to bodily movement of said cam follower means, and a pattern template formed with an endless rack carried in the overhanging portion of said work shifting member and disposed with said endless rack in mesh with said pinion.

2. A buttonhole attachment for a sewing machine comprising an attachment frame adapted to be fixedly secured to said sewing machine, a work shifting member slidably pivoted to said attachment frame, a portion of said work shifting member being formed to overhang in spaced relation above said attachment frame, a cam disk journaled for turning movement on a vertical axis on said attachment frame in the space between said frame and the overhanging portion of said work shifting member, means carried by said attachment frame and adapted to be actuated by said sewing machine for imparting turning movement to said cam member, a sinuous cam groove formed in the upper face of said cam disk, a cam follower member disposed between said cam disk and the overhanging portion of said work shifting member, means on said attachment frame for supporting said cam follower member for bodily movement transversely of said attachment frame, a cam follower depending from said cam follower member and disposed in tracking relation with said cam groove, a pinion rotatably journaled on said cam follower member, means carried on said attachment frame and operatively associated with said pinion to impart turning movement to said pinion in response to bodily movement of said cam follower means, and a pattern template formed with an endless rack carried in the overhanging portion of said work shifting member and disposed with said endless rack in mesh with said pinion.

3. A buttonhole attachment for a sewing machine having a bracket arm in which is journaled a needle carrying bar and a presser bar, said attachment comprising a frame adapted to be secured to said presser bar, a flat horizontal extension formed on said frame, an attachment actuating lever fulcrumed on said frame and adapted to be oscillated by said sewing machine needle bar, a work shifting member slidably pivoted beneath said frame, a work engaging foot carriedby said work shifting member and having an opening disposed for penetration by said sewing machine needle, an upwardly offset portion formed on said work shifting member and disposed in overlying and substantially parallel relation with said flat horizontal frame extension, a cam member journaled on said frame extension, means operatively connecting said attachment actuating lever to said cam member for imparting intermittent turning movementthereto, a cam follower member, means on said cam follower member disposed to track said cam member, means supporting said cam follower member for movement transversely of said attach-v ment frame between said frame extension and the upwardly offset portion. of said work shifting member, a pinion carried above said cam follower member and journaled thereon for bodily movement transversely of said attachment frame with said cam follower member and for turning movement relative thereto, means carried by said attachment'frame for imparting intermittent turning movement to said pinion in response to the bod.ly movement thereof transversely of said attachment frame, a template formed with an endless rack disposed in mesh with said pinion, means for locating said template in a fixed position on the upwardly offset portion of said work shifting member, said locating means being releasable for exchange of said template upon manual lifting of said template upwardly off said work shifting member.

4. A buttonhole attachment as set forth in claim 3 in which the means for securing said template in fixed position on the upwardly offset portion of said work shifting member comprises a body portion formed on said template encompassing said endless rack formed therein, said work shifting member being formed with an aperture loosely accommodating said template body portion, a plurality of ears formed on said template and arranged to span the aperture in said Work shifting member, and mating locating surfaces formed on said template ears and on said work shifting member.

5. A buttonhole attachment as set forth in claim 4 in which the template body portion is formed at each side with a pair of said ears, and the template accommodating aperture in said work shifting member is formed to provide sufiicient clearance at each side of said template between said pairs of ears for reception of an operators fingertips while exchanging said template.

6. A buttonhole attachment as set forth in claim 3 in which a cover is secured to said attachment frame and formed to encase said upwardly offset portion of said work shifting member, said cover being formed with an access opening exposing the vertical projection of said template in any position of engagement of said pinion with said endless rack, and means on said cover shiftable into said cover aperture and into engagement with said template for preventing accidental upward movement of said template.

7. A buttonhole attachment for a sewing machine comprising an attachment frame adapted to be fixedly secured to said sewing machine, a flat horizontal extension formed on said attachment frame, a platform carried on said attachment frame above and substantially parallel to said frame extension, a work shifting member slidably pivoted to said attachment frame, means on said platform for slidably supporting a portion of said work shifting member above and substantially parallel to said platform, a cam member journaled for turning movement on said attachment frame in the space between said attachment frame and said platform, means carried by said attachment frame and adapted to be actuated by said sewing machine for imparting turning movement to said cam member, a cam follower member disposed to track said cam member, means on said platform for supporting said cam follower member and for constraining said cam follower for movement in a predetermined path transversely of said attachment frame in response to movement of said. cam member, a pinion rotatably journaled on said cam follower member in the space between said platform and said work shifting member, means carried on said attachment frame and operatively associated with said pinion to impart turning movement to said pinion in response to bodily movement of said cam follower means, a pattern template formed with an endless rack, and means for securing said template to said work shifting member with said endless rack in mesh with said pinion.

8. A buttonhole attachment as set forth in claim 7 in which said platform above said frame is formed with a straight slot extending transversely of said attachment frame, and said cam following member comprises a plate slidable on said platform, means on said plate engaging said straight slot to constrain said plate for translatory movement across said attachment frame, a cam follower depending from said plate, and means above said plate for rotatably supporting said pinion.

References Cited in the file of this patent UNITED STATES PATENTS 347,133 Smith et al Aug. 10, 1886 442,695 Powell Dec. 16, 1890 2,536,620 Allenby Jan. 2, 1951 2,619,925 Sharenows et a1. Dec. 2, 1952 2,702,515 Almquist Feb. 22, 1955 2,760,453 Enos Aug. 28, 1956 2,804,035 Baehr et al Aug. 27, 1957 2,828,704 Enos Apr. 1, 1958 2,828,705 Enos Apr. 1, 1958 2,890,668 Johnson et a1. June 16, 1959 2,894,467

Thomas July 14, 1959 AIM min-m