Патент USA US2130340код для вставки
Sept 20, 1938- H. J. GALLANT E1- AL ì 2,130,340 TRIMMING MECHANISM FOR SEWIN-GvMACHINES Filed 0G12. 50, 1937 2 Sheets-Sheet l fm1 //. ja Ä ® _ „uw J „3. la, . _ lí@ ‘-lïîlï` 5a 6'0 ’il ,Il 7, HUBE/eT'JT GALL/:NT tie/VEST f7. GAUTH/E/e fig D @mf/KM @Üïow’ißy Sept 20, 1938. H. J. GALLANT E1- AL 2,130,340 ` TRIMMING MECHANISM FOR SEWING MACHINES Filed Oct. 30, 1957 2 Sheets-Sheet 2 2,130,340 Patented Sept. 20, 1938 AUnirse stares ¿PATENT oFFicE 2,130,340 TRIMMÍNG MECHANISM FOR SEWING MACHINES Hubert J. Gallant, Exeter, N. H., and Ernest A. Gauthier, Amesbury, Mass. Application October 30, 1937, Serial No. 171,934 7 Claims. (Cl. 112--125) This invention relates to improvements in trimming mechanism for sewing machines. More especially it provides an improved trim 5 ming mechanism for coaction with the stitching and work-feeding mechanism of a Singer sewing machine of “walking foot” type, having a flat bed as distinguished from a cylindrical bed. Mechanisms for trimming as the stitching pro gresses have heretofore been available for use only on sewing machines not having a “walking foot” feed, or on “walking foot” machines having a cylindrical bed; and have been complicated and cumbersome devices. No one, so far as we are aware, has successfully combined a trimming mechanism, in a simple and unobtrusive practi 40 50 55 invention disclosed. ’ In the acompanying drawings: ' Figure 1 is an end elevation of a sewing ma~ chine head, embodying features of the invention; Figure 2 is an elevation looking from the leftv in Figure 1 at the rear side of the head; Figure 3 is an elevation of the lower portion of the head, looking from the right in Figure 1 at the front side of the head; Figure 4 is an elevation of the lower portion of ¿e the head, looking from the left in Figure 2; feeding mechanism of a “walking foot” iiat bed Figure 5 is a plan, in section on 5_5 of Figure l; Figure 6 is a plan of the bed plate; and Figure '7 is a view like Figure l of the lower por tion of the head, but with the trimmer plate and 20 a trimmer mechanism which is simple, as com 35 ever features of patentable novelty exist in the cable form, with the regular stitching and work type of sewing machine. The invention has among its objects to provide 30 under side of the plate, to support the incidental cut end of the shearing bar of the plate. It is intended that the patent shall cover, by suitable expression in the appended claims, what blade in elevated inoperative positions. pared with devices now available, and, for mount Referring to the drawings, the invention is por~ ing and guiding the trimmer blade, to utilize for the most part present standard sewing machine trayed as embodied in a “walking foot” type of Singer sewing machine, which has an usual head elements. Another object is to provide simple yet effec- « Iii, needle bar I2 and presser bar I4. The needle tive connections for actuation of the trimmer bar and presser bar are mounted side by side in ' the head, for vertical reciprocation in timed reblade in timed relation to the sewing and work lation by usual mechanism (not shown) Within feeding functions of the machine. » the head. The needle I6 is carried at the lower A further object is to provide means for the op erator to throw the trimmer mechanism into and end of the needle bar; and the presser foot it is „ 30 carried at the lower end of the presser bar, forout of action, at will, without affecting the regu co-acting with the corrugated feed dog 20 which lar functions of the machine. It is another feature that the bed plate for use works in the slot 86 in the flat bed plate 22 of the with the trimmer can be made as a modification machine. A walking foot 24 is mounted on the lower end 35 of one which is already available as a standard of a bar 26 which hangs by gravity from its pivotal type. . mount at 28 on an L-shaped lever 3i). A leaf For holding the trimmer blade, the inventio provides a plate guided slidably on the presser spring 32 urges this bar forward so that its foot bar of the machine, below the machine head. A 2d engages the presser foot I8, at the times when second guide element may be fixed in the under the Walking foot is elevated with respect to the_« 40 face of the head, for combining with the presser work. The Walking foot 24 and its suspension bar 2G bar to maintain the plate in a horizontal plane, and to ~hold it against turning. A latch link is are actuated in vertical directions by a crank arm adapted to engage the plate operatively when the 34 on rock shaft 3B. Mechanism (not shown) plate is pressed downward, so that the plate 'and within -head Ill, reaching out at the back of the . its blade are reciprocated by the latch link which. head, rocks shaft 36 in timed relation to the move- ` is itself reciprocated by a link of the regular ments of the needle bar and presser bar. A link 33 connects crank arm 34 to one arm of the L “walking foot” actuating mechanism. A disen gaging of the latch lets a spring move the trimmer shaped lever 36, whose other arm is connected to a block ¿lil which is secured to and carried by they to its uppermost position where it is inoperative. A bed plate of the sort used with trimmers on presser bar I4, and which is slidable vertically on machines not of the “walking foot” type may be the fixed guide 42. The foregoing is descriptive of mechanism modified to suit our present requirements, by con verting the rectangular feed slot to an inverted which is old and well known. In operation, the L-shaped slot, and by providing a bracket on the >presser foot engages and holds the work between.Í 2 2,130,340 itself and the feed dog 20 while the needle pierces the Work. As the needle is being elevated, the walking foot 24 is moved downward into engage ment with the work, and the presser foot I8 is ele 5 vated a little to disengage itself from the work. Then the feed dog 20 moves rearward, and the work is carried with it, pinched between the feed dog and the walking foot which moves rearward against its leaf spring 32. As the needle starts 10 downward, the presser foot I8 again engages the Work, the walking foot 24 is lifted, and spring 32 swings it back to its forward position. According to the invention, a horizontal plate 44 for carrying the trimmer blade 50 is mounted 15 below head i8 and can be adjusted vertically be tween a depressed position as represented in Fig ures 1-4, where it is operative through a range of vertical travel, and an elevated position, as seen in Figure 7, where it is inoperative. A con 20 venient arrangement is to mount plate 44 slid ably on the presser bar I4, and on a short, ñxed post 45 which is secured in the head to project downward parallel to the presser bar. A coil spring 48 tends to draw plate 44 to its upper in 25 operative position of Figure 7. A A trimmer blade 50 is secured on plate 44, ad justably as` by the screws 52, the particular blade shown being of a well known variety heretofore used on other types of sewing machines. In the 30 upper position of plate 44, the blade 50 is elevated well above the level of the work on bed plate 22. The invention coordinates the operations of the walking foot and trimmer so that the trimmer blade, when depressed and connected for opera 35 tion, makes a downward cutting stroke each time the walking foot is lifted from the work at the end of each feed advance of the work. To this end, a bell crank is pivoted at 54 on a ñXed part of the head I8. One arm 56 of the bell crank is 40" secured to the link 38 at a mid-location 68, and the other arm 52 of the bell crank is connect ed at 64 to a latch-link 66 whose lower end eX tends within a slot 68 (Figure 5) in plate 44. A notch 'I8 near the lower end of the latch-link 45 is adapted to engage the rounded edge wall 'l2 of slot 58, thereby to connect the plate operatively with the latch-link. A leaf spring 14 continually urges latch-link G5 against said edge 12 so that, when the plate 44 is moved downward, as by a 50 person pressing down on ñnger piece 16, the latch-link snaps into plate engagement. The plate and the trimmer blade 50 which it carries are then reciprocated vertically by movements of link 38. The trimmer thus can function in timed rela 55 tion to the stitching and feeding of the work. And, quite as important, the trimmer may be thrown outl of service by means of handle '|8, by merely disengaging latch-link 66. Figure 6 shows in plan an improved bed plate 22 devised especially for coacting with the de scribed trimmer attachment. It is provided with a slot 88 which, as viewed from the front, is in the shape of an inverted L, within the breadth of 65 whose longer limb the feed dog 28, the presser foot I8 and the walking foot 24 may coact for the holding and-for the feed, with the walking foot extending laterally into the space occupied by the broad sharter limb of the L. A trimmer 70 plate of a shape used on another type of sewing machine, having a straight slot, may be modiñed to suit the requirements, by removing a portion of the adjacent metal strip 86 which is present 60 in that type, and by providing a bracket 82 on 75 the under face of the bed plate, with finger 84 for supporting the cut end, at what was the mid dle, of this metal strip 86. A usual spring pressed block 88 yields, as the blade is forced down through the crack at 90, and meanwhile yieldingly presses the trimmer blade against the strip 86, for shearing action. The needle passes down through hole 92 in strip 86. The invention involves few parts and may be embodied in standard sewing machines of well known types without disturbing present mech 10 anism. In Figure 6 the bed plate 22 is shown as it would appear in plan when standing at the back side of the machine, i. e., the slot has the de scribed inverted L shape when viewed from the 15 front side of the machine. We claim as our invention: 1. In a sewing machine having a work sup port and stitch forming mechanism, with work feeding mechanism and a head overhanging, in 20 cluding a presser bar with presser foot, a walking foot, and actuating means therefor; the com bination therewith of a trimmer blade having mounting means slidable on the presser bar below the said head; means for connecting said blade 25 to said actuating means at the will of the opera tor, for reciprocating the trimmer blade in timed relation to the action of said work-feeding mech anism. 2. In a sewing machine having a work support 30 and stitch forming mechanism, with work-feeding mechanism and a head overhanging, including a presser bar with presser foot, a walking foot, and actuating means therefor; the combination therewith of a plate mounted slidably on the 35 presser bar, below the said head; a trimmer blade ñxed on said plate; means for connecting said plate to said actuating means at the will of the operator, for reciprocating the trimmer blade in timed relation to the action of said work-feed 40 ing mechanism. ’ 3. A sewing machine as in claim l, wherein the said connecting means is a lever pivoted on said head and having one arm connected to said ac _tuating means; and means at the other arm of said lever for operative connection to the slidable means. 4. A sewing machine as in claim 2 wherein the said plate is ,yieldingly held by a spring in an ele vated inoperative position, and wherein said con 50 necting means is a lever pivoted on said head and having one arm connected to said actuating means, and its other arm carrying a latch-link suspended and spring-pressed into sliding en gagement with an edge of said plate; said latch link having a notch therein adapted to move into latching engagement with the plate when said plate is depressed to latch-engaging level. 5. A sewing machine as claim 1 wherein said mounting means for the trimmer blade is addi 60 tionally guided by a guide post projecting down ward from said head in parallelism with said presser bar. 6. A sewing machine having a head, a presser bar with presser-foot mounted for reciprocation in the head, a trimmer blade, a guide post pro jecting from said head, at a distance from said presser bar and parallel thereto, a carrier for said blade mounted slidably on said presser bar and said post, and means, actuated in timed rela tion to said presser bar, adapted for'actuating connection to said blade carrier, whereby the said blade carrier moves in timed relation to the presser bar. 7. A sewing machine as in claim 1 wherein the 2,130,340 machine has a flat bed with a ñat bed plate which has an inverted L~shaped slot for accom modating the feed dog and Walking foot, and has a bar set along the vertical limb of the L, hav ing a hole for passage of the needle, said bar con stituting one blade of a shear, and ending with in the inner angle of said L, and wherein the un der side of said bed plate has a bracket sustain ing the end of the shear bar, and the upper side 10 of said bed has, in the plane of the shear bar, a 3 block yieldingly urged laterally against said shear bar, said block having a groove in its edge for reception of the leading end of said trimmer blade between said block and said bar, with said block yielding away from the shear bar as the 5 blade moves downward, whereby said block presses said blade into shearing relation with said shear bar. HUBERT J. GALLANT. ERNEST A. GAUTHIER.