US 3361098 A
Description (OCR text may contain errors)
Jan. 2, 1968 A. SEAMAN 3,361,098
POCKET SLIT EDGE CUTTER Filed Feb. 7, 1966 5 Sheets-Sheet 1 INVENTOR flrzhur Seaman Jan. 2, 1968 SEAMAN 3,361,098
POCKET SLIT EDGE CUTTER Filed Feb. 7, 1966 3 Sheets-Sheet 2 INVENTOR Ari/7dr 5e amah BY WW Jan. 2, 1968 A; SEAMAN 3,361,098
POCKET SLIT EDGE CUTTER Filed Feb 7, 1966 3 sheets-sheet s YT 5 Y 5'? l I 85 \M 60 Z /7 V 4; INVENTOR 0 5g flrf/mr Seaman AUDRNES V United States Patent This invention concerns an attachment for a double needle sewing machine, the attachment being used to cut material between two lines of stitching while sewing on piping, cording or other trimming material.
The attachment operates while the machine is sewing the two lines of stitching. According to the invention, the attachment has a slide mechanism which can be retracted and locked in place for positioning a spring biased knife under the needle drive bar of the sewing machine. As the needle drive bar goes up and down during a sewing operation the knife moves with it up and down and cuts the material between the two needles each time the knife descends. A slide release lever is provided to effect withdrawal of the slide device and knife when the cutting mechanism is to be deactivated. The attachment mounts on the stationary head of the sewing machine. The attachment may be provided with rod insert blocks for supporting any desired kinds of folding elements for cording, piping, etc.
It is therefore a principal object of the invention to provide an attachment for a double needle sewing machine, with the attachment having a spring biased knife driven by the needle drive bar of the machine for cutting material between the needles, While sewing two lines of stitching.
A further object is to provide an attachment as described, wherein a slide device mechanism carries the knift and is movable inwardly against spring tension, the head of the machine supporting the attachment, and wherein a spring biased slidable latch bar holds the slide device in position for actuation of the knife by the needle drive bar.
Another object is to provide an attachment as described, wherein a lever is secured to the latch bar for retracting it to release the slide device for withdrawing the knife out of the line of travel of the needle drive bar.
For further comprehension of the invention, and of the objects and advantages thereof, reference will be had to the following description and accompanying drawlugs and to the appended claims in which the various novel features of the invention are more particularly set forth.
In the accompanying drawings forming a material part of this disclosure:
FIGURE 1 is a front elevational view of an attachment embodying the invention, parts being broken away to show inside construction, the attachment being shown mounted on a sewing machine head, with part of an associated sewing machine table shown in section.
FIG. 2 is an end elevational view of the attachment, the knife being shown in deactivated position.
FIG. 3 is an end view similar to FIG. 2, the knife being shown in operating position.
FIG. 4 is a top plan view of the attachment.
FIG. 5 is a vertical sectional view taken on line 5-5 of FIG. 4.
FIG. 6 is a fragmentary plan view of a piece of double stitched material showing the type of work done by the attachment.
Referring first to FIGS. 15, there is shown a stationary sewing machine head 10 disposed over a horizontal sewing table 12. The table has feed dogs 14 which advance material placed over them in cooperation with presser feet 16 over foot and needle plate 17. The presser feet are carried by a presser bar 18 supported in head 10. The head also carries a needle drive bar 19 having a cross member 20 to which are attached two spaced apart vertical needles 22. The parts of the sewing machine are conventional and are illustrated and described in order that the structure and function of the sewing machine attachment 25 may be better understood.
The attachment 25 has a mounting plate 26 which is disposed in a vertical position when the attachment is in use. Screws 23 at plate 26- are used. to secure the attachment to the front side of head ltl. Plate 26 has a narrow rectangular section 30 which extends to the left as best shown in FIGS. 1 and 4. At the lower left corner of plate section 30 is secured a block 32. This block has a horizontal bore 33 to receive a rod support for a folding element (not shown). Screws 34 in block 32 may be used to secure the rod support in the block. Another similar block 35 provided with screws 36 is located at the bottom edge of plate 26.
Secured to plate 26 by screws 38 is a stationary latch block 40. This block has a pair of spaced abutments 41, 42 in which is slidably disposed a horizontal latch bar 44. An operating lever or handle 46 is engaged with bar 44 at spaced points at opposite sides of abutment 42 and is secured by bar 44 by screws 47, 48. The handle terminates in an upwardly turned finger grip 49 which can easily be grasped for pulling the bar 44 to the right. A coil spring 50 on bar 44 is engaged between abutment 42 and an abutment 51 formed on the left end of handle 46. Screw 47 is seated in abutment 51 formed on the left end of handle 46. Screw 47 is seated in abutment 51 to engage bar 44 thereat. The coil spring 50 tends to urge bar 44 and handle 46 to the left, so that the bar and handle can be retracted against tension in spring St). The bar 44 has a pointed left end 55. This end of the bar fits into a hole 56 formed in an L-shaped slide plate 58. Plate 58 has a leg 59 disposed vertically and perpendicular to leg 60. Hole 56 is formed in leg 60. Leg 519 is disposed forwardly in a convenient position for being pushed rearwardly by the operator of the sewing machine. Leg 60 has a narrow extension 62 which is disposed perpendicular to plate 26 and which extends slidably through a slot 53 formed in plate section 30.
Slide plate 58 is supported by a pair of stationary axially horizontal rods 64, 65 having threaded ends d6 screwed into threaded holes in plate section Fall. The rods are disposed perpendicular to plate 26 and are disposed in a common vertical plane. Coil springs 67, 68 are provided on rods 64, 651 These springs bear against plate section 30 and against a block 7t] integrally formed with plate leg 69 and extending to the left therefrom. The rods 64,
65 are slidably disposed in bores 72 in block 70. A stop element 75 is screwed into the free end of plate extension 62. This element bears against the rear side of plate 26 to hold the slide plate in outwardly extended position shown in FIG. 2. i
A triangular abutment 73 is formed at the left end of block '70. A vertical plate 76 extends forwardly from block 7t) spaced to the right of plate leg 60 and parallel thereto. A knife arm 8th is pivotally held on plate 76 by a screw 82. The arm has a narrow extension 81 at its upper end carrying a pin 83 to which is secured the upper end of a coil spring 8 2-. Thelowcr end of the spring is attached to a pin 85 secured to a bottom corner of plate 76. The spring 84 biases the knife arm in clockwise direction as seen in end views of FIGS. 2 and 3. When the slide plate 53 which carries the knife arm is in forward extended position the rear edge 86 of the knife arm bears against abutment 73 as shown in FIG. 2. A knife 88 with a sharp downwardly and rearwardly inclined cutting edge 89 is secured to the bottom end of the knife arm by screws 99. The back edge 92 of the knife normally disposed in a slightly downwardly inclined position as shown in FIG. 2 spaced forwardly of cross member 20. The knife is disposed. in a vertical plane which intersects member 29 between needles 22. A slot 95 is provided in the plate 17 and table 12 between the feed dogs 14. This slot 95 receives the cutting edge 89 of the knife when the knife is operated as shown in solid lines in FIG. 3.
When the slide mechanism, including slide plate 58, the knife arm 8i and knife 88, is moved rearwardly by manual pressure applied to plate leg 59, the knife arm moves rearwardly in a vertical plane until the back edge 92. of the knife is positioned underneath the cross member 20. This position of the parts is shown in dotted lines in FIG. 3. Then when the needle drive bar 19 moves down, the cross member 20 pushes the knife down to cut material M shown in FIG. 5. When the drive bar moves up, the coil spring 84 pivots the knife arm up so that the back edge of the knife always remains in contact with cross member 20. While the needles 22 sew two lines of stitching S, knife 88 cuts slit SL in the material M. FIGS. 5 and 6 show the material M to which two lines of piping P1, P2 have been attached by stitching lines S and simultaneously slit has been formed in the base or bottom material M.
The slide mechanism remains in retracted position with knife 88 operative due to engagement of the pointed end 55 of bar 44 in hole 56 in plate leg 60. When it is desired to deactivate the knife, the handle 46 is pulled manually to the right against tension in spring 50. This withdraws latch bar 44 from hole 56 and releases the slide plate 58, Springs 67, 68 then expand and the slide plate along with the knife arm are pushed forwardly away from the path of travel of the cross member 29 and needle drive bar 19. The handle 46 can then be released and the spring 50 will expand until the pointed end of bar 44 bears against an imperforate point on plate leg extension 62.
The attachment is especially useful when pocket slits or other slits are formed in fabric M, while trimming is being sewed to the edges of the slits. The attachment is entirely mechanically operated and requires no drive motor, electromagnet or special drive means, since it employs the needle drive bar itself for motive power. Furthermore it operates in complete synchronism with the needle drive bar which is a very great advantage, as each stitch is sewn, a further slight cut is made between the stitches and dogs 14 pull the fabric rearwardly. Thus there is no danger of excessive cutting of the material. The knife can be quickly and easily deactivated or activated at will. When not in use, the attachment does not interfere with operation of the sewing machine in any way. Any desired rolling or folding attachments can be mounted to the blocks 32 and 35.
The attachment is easy to install, is of sturdy construction and will provide long, trouble-free, satisfactory service.
While I have illustrated and described the preferred embodiments of my invention, it is to be understood that I do not limit myself to the precise construction herein disclosed and that various changes and modifications may be made within the scope of the invention as defined in the appended claims.
What is claimed is:
1. An attachment for a double needle sewing machine for cutting material between two lines of stitching while the material is being stitched, said machine having a stationary head supporting a reciprocable needle drive bar carrying a cross member, said cross member carrying two vertical needles spaced apart; said attachment comprising a mounting plate attachable to said stationary head in a vertical position, a slide mechanism on said mounting plate movable between a rearward retracted cutting position near said plate and a forward extended inoperative position away from the plate, latch means for holding the slide mechanism in retracted position, a downwardly extending knife arm pivotally carried by said slide mechanism, a spring pivotally biasing said arm to a raised position above said material, a knife carried by said arm disposed in a vertical plane, said plane intersecting said cross member when said plate is attached to said head, and said knife having a downwardly oriented cutting edge and an upper edge downwardly inclined with respect to a horizontal plane, said upper edge of the knife being disposed under said cross member when the slide mechanism is latched in the retracted rearward cutting position, whereby the cross member moves said knife downwardly against the bias of said spring to out said material when the needle drive bar moves downwardly, and the knife moves up with the needle drive bar in continuous engagement with said cross member under the bias of said spring so that a slit is made in the material between the needles While the needles sew two parallel lines of stitching in the material and said upper edge being free from engagement with said cross member when said slide mechanism is in said forward extended inoperative position.
2. An attachment as recited in claim 1, wherein the slide mechanism comprises an L-shaped slide plate having a vertical forwardly located leg adapted to be pushed rearwardly to retract the slide mechanism, said slide plate having a second leg, an extension on said second leg, said mounting plate having a slot therein, said leg extension extending perpendicular to the mounting plate through said slot, and a stop element on the free end of the leg extension for holding the slide plate in extended position with respect to the mounting plate.
3. An attachment as recited in claim 2, further comprising a block secured to said second leg, a pair of rods secured to the mounting plate and extending through bores in said block, and springs on said rods normally biasing said slide plate into said extended position while said stop element bears against said mounting plate.
4. An attachment as recited in claim 3, further comprising a second plate secured to said block, said knife arm being pivotally mounted on said second plate, and a pair of support pins, the first named spring being secured between said support pins, one of said pins being located on an upper end of the knife arm and the other of said pins being located on said second plate.
5. An attachment as recited in claim 1, further comprising a pair of bored blocks secured to said mounting plate for mounting and supporting fabric rolling and folding attachments.
6. An attachment as recited in claim 2, wherein said latch means comprises a stationary latch block secured to the mounting plate, a latch bar slidably supported by said latch block, a handle secured to the latch bar for retracting the same axially, and a coil spring on the latch bar normally biasing the latch bar toward said second leg of the slide plate, said second leg having a hole for receiving a free end of the latch bar to hold the slide mechanism in retracted position.
7. An attachment as recited in claim 3, wherein said latch means comprises a stationary latch block secured to the mounting plate, a latch bar slidably supported by said latch block, a handle secured to the latch bar for retracting the same axially, and a coil spring on the latch bar normally biasing the latch bar toward said second leg of the slide plate, said second leg having a hole for receiving a free end of the latch bar to hold the slide mechanism in retracted position, whereby the slide mechanism is extended by the springs on the rods when the r arm being pivotally mounted on said second plate, and a' pair of support pins, the first named spring being secured between said support pins, one of said pins being located on an upper end of the knife arm and the other of said I 7 pins being located on said second plate.
6 9. An attachment as recited in claim 7, further com- References Cited prising a pair of bored blocks secured to said mounting UNITED STATES PATENTS plate for mounting and supporting fabric rolling and 218,151 8/1879 Wilson 112125 f ldmg attachments 1,861,068 5/1932 Routtenberg 112--128 10. An attachment as recited in claim 6, further com- 5 2,617,374 11/1952 De Robertis 112-122 prising a pair of bored blocks secured to said mounting plate for mounting and supporting fabric rolling and fold- JORDAN FRANKLIN, P r 1mm) Exammering attac m nts H. H. HUNTER, Assistant Examiner.