US3054366A - Lapped seam trimmer - Google Patents

Description

p 18, 1962 w. c. CREMER 3,054,366

7 LAPPED SEAM TRIMMER Filed June 12, 1959 Fig.5.

2 Sheets-Sheet l INVENTOR. William C. Cremer ATTORNEY p 1962 w. c. CREMER 3,054,366

LAPPEID SEAM TRIMMER Filed June 12, 1959 2 Sheets-Sheet 2 INVENTOR. William C. Cremer ATTORNEY 3,054,366 Patented Sept. 18, 1962 ice 3,054,366 LAPPED SEAM TRIMMER William C. Crerner, 1312 Lancaster Ave, Reading, Pa. Filed June 12, 1959, Ser. No. 820,024 2 Claims. (Cl. 112-123) This invention relates to a trimming attachment or trimmer for a sewing machine and, more particularly, to a trimmer especially designed for trimming the under portion of a lapped seam, particularly where elastic is used as a top portion or as a band, such as on the top of cotton shorts.

It is known in the art to use trimmers of the shear action cutting type in sewing machines for severing one or more plies of material as the material proceeds through the machine in the process of stitching.

An outstanding disadvantage of conventional trimmers is that they are relatively complicated in construction and often require modification of the construction of the sewing machine, also they are deficient in many respects, for example, they do not permit sewing elastic or band in loop form to a garment since they do not permit completing the circle to form an endless loop in the trimming operation, or permit ready removal of the garment from the machine.

An object of my invention is to provide a novel lapped seam trimmer which is devoid of the above named disadvantages and which will enable the trimming of the under portion of a lapped seam in synchronism with the knitting operation, particularly where elastic is used, such as the top portion or band on the top of cotton shorts.

A further object of the invention is to provide a compensating presser foot for seaming elastic which has been cut and sewn in loop form to the tops of cotton shorts or to other items onto which bands of a similar character are sewn.

Other objects and advantages of the present invention will become more apparent from a study of the following description taken with the accompanying drawings wherein:

FIG. 1 is a front elevational view of a fragmentary portion of a sewing machine which has been equipped with a lapped seam trimmer embodying the principles of the present invention;

FIG. 2 is a side elevational view of a portion of the machine and the attachment shown in FIG. 1;

FIG. 3 is a perspective view of a lapped seam trimmer embodying the present invention wherein the regular presser foot has been eliminated for the purpose of clarity;

FIG. 4 is an enlarged, top view of the upper and lower blades shown in FIGS. l3;

FIG. 5 is a top or plan view of the presser foot and auxiliary presser foot; and

FIG. 6 is a front or elevational view of the presser foot assembly shown in FIG. 5.

Referring more particularly to FIGS. 1, 2 and 3 of the drawings, numeral 1 denotes a fragmentary portion of a sewing machine head, such as that of Union Special 52-700 machine basically described in US. Patent 2,670,- 703, although it should be understood that other machines may be also used for making a similar type of stitch, particularly since machines for making the same type of stitch are of the same basic design. Supported on the head is a needle holder 2 holding a needle 3. On the base or frame portion 4 of the sewing machine there is supported a regular feed device 5 which cooperates with a regular foot 6 as shown more clearly in FIGS. 2, 5 and 6.

The lock seam trimming attachment or trimmer in accordance with the present invention is a unitary assembly mounted on a mounting base 7, which base is secured to the frame 4 by a bolt, screw or any other suitable fastening means and serves as a support for the entire lapped seam trimming attachment. The trimmer is driven by the conventional feed dog drive eccentric or stitch regulator cam on the sewing machine (such as element 60 in FIG.

3 of said Patent 2,670,703), element 15 being a special 5 yoke secured to such cam for driving the trimmer. At-

tached to the yoke 15 is an arm 16 and hub portion 17 which drives the feed dog. The yoke 15 is connected by link 14 to a link or lever 13 which, by set screw 13a, is adjustably secured to different angular positions on shaft 9a so as to selectively adjust the height of the upper blade 19. Upper blade 19 is secured to an upper blade holder 9 which in turn is rigidly secured to the end of shaft 9a. By virtue of the adjustment of collar 11 against a coil spring 12, selective adjustment of the compression of such coil spring is obtained for selecting the amount of friction between the oscillatable upper blade 19 and the relatively stationary lower blade 20. The lower blade 20 is connected to a lower blade holder 8. A pair of bearings are provided for rotatably supporting the shaft to which the upper blade holder 9 is attached.

FIG. 4 more clearly shows the shearing action, illustrating the lower blade 20, the upper blade 19, the trimmed fabric 29 and the entering fabric 28, also the elastic 27.

An important feature of the present invention is the special presser assembly which is shown more clearly in FIGS. 2., 5 and 6. Numeral 21 is the auxiliary presser foot bar which is mounted on the sewing machine presser bar above the conventional or regular presser foot 6 (which is omitted in FIG. 3) having a regular feed 5. The foot shank 22, which is pivotally mounted on bar 21, holds presser foot 23 which pivotally moves up and down with the special feed dog relative to bar 21. The special feed dog is underneath the special presser foot 23 and mounted with the regular feed dog screw to the side of and to the front of the regular feed dog so as to feed the cloth under special feed dog 23. A stop pin (see FIG. 5) in foot regulator bar 24 keeps the special foot from dropping below the level of the regular presser foot, also it applies the necessary tension through spring 25 to press shank 22 against stop pin 24a. This special presser foot assembly shown in FIG. 3 is made to fit around the top blade 19 (see FIG. 3) and make possible the feeding and holding of the fabric to be trimmed and at the same time allow the elastic or band to run over the top of the special foot and under the regular foot where it is sewn. It should be especially noted, as shown more clearly in FIG. 5, that there is a lateral separation between the special foot 23 and the regular foot 6 to which it is attached. Now in loop form, if it were not for the separation between the special foot and regular foot, it would not be possible to finish the circle or loop or remove the garment from the sewing machine. The trimmer is very useful in sewing an elastic or band to a garment which must be trimmed before it is sewn. The special foot and front feed 30 are mounted on the side of the regular foot 6 or feed and is closely alongside of the lower blade 20, therefore makes for a better control and feed of the cloth which is to be trimmed.

The special or compensating presser foot assembly shown in FIG. 3 enables the seaming of elastic which has been sewn in a hoop form to the tops of cotton shorts, or for other applications in which bands are sewn on in this fashion.

It enables the operator to lift the under piece to the top of the special foot to complete the sewing operation.

The special foot operates on feed 30 and holds and controls under fabric and allows the top elastic or fabric, which is in loop form, to pass easily over the trimmer blade. Without such foot and feed it is nearly impossible to sew loop elastic or bands to garment where a trimmer 70 is used.

Thus it will be seen that I have provided an efiicient trimmer in the form of a unitary assembly mounted on a single base which can be easily and quickly mounted on a my invention and Within the scope of the following claims.

I claim: 7

1. In a sewing machine having a feed dog and drive therefor and a regular presser foot thereabove and cooperable therewith, in combination, a shear action trimmer driven by said feed dog drive, mounting means adapted to be secured to a presser bar above said regular presser foot, said mounting means including horizontally extending pivot means, a special foot spaced laterally and forwardly of said regular presser foot and being rotatable about said pivot means, a special feed dog underneath said special foot and cooperable therewith, a regulator bar stationarily secured to said pivot means, a stop pin extending from said regulating bar into the path of movement of said special foot thereby limiting the downward movement of said special foot toward said special feed dog, and a spring normally biasing said special foot against said stop pin, 'there being aspace between the'bottoms of said regular and special feet to permit introduction and withdrawal of cloth therethrough, whereby such'cloth may be introduced and sewn in the form of an endless loop and removed as such through said space.

2. Apparatus as recited in claim 1 wherein said feed dog drive includes a cam, a yoke adaptedto be attached to said cam for driving the trimmer, said trimmer comprising an oscillatably mounted cutter operated by said yoke, a stationary blade, adjustable link means connecting said yoke to said cutter to adjust the height of the cutter relative to said stationary blade, and adjustable spring means for adjusting the friction between said cutter and blade of said trimmer to vary the shearing action.

References Cited in the file of this patent UNITED STATES PATENTS 2,288,404 Kahre June 30, 1942 2,627,240 Johnson et a1. Feb. 3, 1953 2,893,336 Chinnici July 7, 1959

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