US2673539A - Shoe inseam sewing machine - Google Patents

Description

March 30, 1954 F. c. EASTMAN 2,673,539 SHOE INSEAM SEWING MACHINE Original Filed Jan. 29, 1949 2 Sheets-Sheet l Inventor Fred C Eastman 1,

March 30, 1954 F, c. EASTMAN SHOE INSEAM SEWING MACHINE 2 Sheets-Sheet 2 Original Filed Jan. 29, 1949 Inventor Fred C Eastman Patented Mar. 30, ,1954

2,673,539 SHOE INSEAM SEWING MACHINE Fred C. Eastman,

Marblehead, Mass., assignor to United Shoe Machinery Corporation,

Flemington, N. J., a corporation of New Jersey Original application January 21, 1949, Serial No.

71,990, now Patent No. 2,647,478, dated August 4, 1953. ..Divided 1952, Serial No. 292,672

2 Claims. (01. 112-55) The present invention relates to improvements in looper actuating mechanisms for shoe inseam sewing machines of the type disclosed in United States Letters Patent No. 1,971,575, granted August 28, 1934 upon application of Alfred R. Morrill and in a copending application for United States Letters Patent Serial No. 71,990, filed January 21, 1949 in the name of the present inventor, of which latter application, the present one is a division and from which Patent No. 2,647,478 has been granted August 4, 1953. In the machine of the Morrill patent, the stitch forming devices comprise a curved. hook needle, a needle looper and a thread measuring finger arranged with the needle to be engaged with the thread by the needle looper before the thread is laid in the hook of the needle. To enable the needle, as it retracts from the work, to draw a loop of thread unrestrictedly through the work without any tendency of the thread to slide in the hook of the needle, the thread finger gives up thread to the needle from between the last formed stitch in the work and the needle. It has been found that in the machine of the Morrill patent it frequently is desirable to increase the movements of the needle looper so that reliable engagement of the thread with the thread finger and needle may be insured. On account of the construction in the needle looper actuating mechanism, however. difficulties are encountered which increase the friction on the parts of the looper actuating mechanism and tend to cause the parts to become cramped at the extremities of their movements. It is accordingly an object of the invention to provide, in a machine of the type referred to in the Morrill patent, a simple and improved looper actuating mechanism capable of imparting to the needle looper a greater movement than is possible with the patented machine without undue friction or liability of cramping the parts of the actuating mechanism, one with relation to another.

The mechanism for actuating the needle looper of the Morrill machine includes two independent actuator arms arranged for rocking movement about a single supporting shaft disposed in parallel relation to a main sewing shaft having cams engaged by followerson theiactuating arms. .B tween theactuating arms there is connected by means of universal ball-and-socket joints two arms of a Y-shaped support, the third arm of which has secured to it the looper. The connections of the looper actuating mechanism, including the follower arms and th Y-shaped support, are statisfactory in their operation so longf-flas limited movement is imparted by the actuator Preferably,

and this application June 10,

arms to the support. If the movements of the actuating arms, however, are increased beyond a limited range, a foreshortening action occurs be tween the arms of the support and the actuator arms so as to cause undue friction and cramping in the ball-and-socket joints connecting the arms to the support. Also the frictional action causes undue wear on the shaft about which the follower arms rock.

To obviate the effect of friction and cramping action in the independent actuators or cam follower arms and the looper support of the machine embodying the present invention, one arm of the Y-shaped support of the Morrill patented construction is disconnected from its actuator or follower arm and a separate link is interposed between it and the actuator so that foreshortening actions in the distance between the actuators and in the support will no longer cause undue friction to be applied to the arms and the support. the separate link is connected to the support by a pivotal joint having bearing surfaces extending in the same general plane with the support to prevent any tendency of displacer ment of the support from its operating plane.

These and other features of the invention consist in the devices, combinations and arrangements of parts hereinafter described and claimed which, together with the advantages to be obtained thereby, will readily be understood from the following detailed specification taken in connection with the accompanying drawings in which:

Fig. 1 is a viewin right side elevation partly broken away and shown in section, of a portion of a shoe being operated upon and of the head of a shoe inseam sewing machine embodying the features of the invention;

Fig. 2 is a sectional detail view in right side elevation of I a portion of the looper actuating mechanism illustrated in Fig. 1; and

Fig. 3 is a plan view of the looper support'and its actuating mechanism.

The shoe machine illustrated in the drawings is constructed and arranged to sew the upper and the welt to the insole of a welt shoe and is provided with a curved hook needle 2, a needle ldoper 4,'a channel guide 6,' atakeup 3, a thread finger'lflg ahvelt fguide l2 and other stitch forming and work engaging devices similar, except as hereinafter described, to those of the Morrill patent and to those of inventors application above identified. The stitch forming devices are driven from a main sewing shaft I 4 rotatably mounted in a frame l6.

During each sewing cycle of the machine the finger and needle, it is sometimes necessary to increase the limits of looper movement beyond those for which the looper actuating mechanism of the Morrill patent is effective.

As in th machine of the Morrill patent, the present machine is provided with a mechanism and a mounting for the looper 4 comprising a Y-shaped three-cornered and three-armed support It; to one arm of which the looper is secured as shown in Figs. 2 and 3. The looper carrying arm of the support 18 is confined vertically and slidably, mounted between a surface on the machine frame and a bearing member 20 secured to the machine frame. The other remaining divergent arms of the support are each universally and operatively connected by ball studs 2| to one of two independent actuators or arms 22 and 24 fulcrumed to swing in spaced parallel planes on a fixed shaft 26, the actuators moving the support bodily and guiding the looper movements while the thread is being laid in the hook of the needle. To connect the support with the actuator arms in the machine of the patent, the arms are provided with socket portions engaging directly with the ball studs which are mounted on the actuator arms, the arms being operated by followers engaging cam on the sewing shaft Hi. In the machine of the patent, there is a tendency for the actuator arms to be subject toundue frictional effect and transverse torsion in their rocking movements about the shaft 26, particularly if cams are employed, the tracks of which increase the movements beyond a limited range and the bearing surfaces on the frame and on the member 20 are constructed within close fitting tolerances. This undue frictional effect is the result of the foreshortening movements of the support l8 which is directly connected between the two arms, the support defining a plane at right angles to the planes of the actuator arms.

In the present illustrated machine the frictional effect on the actuator arms 22 and 24 as a result of the foreshortening movements of the looper support I8 is avoided by the use of a separate link 28 interposed between one arm of the support l8 and its actuator arm 22 to form an operative connection between the support and its actuator arm as distinguished from a direct connection. The link 28, in turn, has a socket portion engaging with a ball member 2| on the arm 22 in place of the socket directly on the support of the patent and is perforated to receive a cylindrical hinge pin 30 passing through the forked end of the support IS. The forked end of the support is disposedwith lateral bearing surfaces for the link 28v extending in planes parallel with-the generalplane of the support so that displacement of the support from its plane will be avoided while movement of the link on the arm 22 within the general plane of the support is not restrained. With the use of the link 28 any foreshortening movement of the support between its points of connection with the arms 22 and 24 imparts a swinging movement to the link 28 about the pin 30 without exerting any undue torsional force on the support such as will cause undesirable frictional reaction on the arms 22 and 24. Since the swinging movement of the link 28 is confined by its lateral bearing surfaces, improper movements of the support as the link swings are avoided.

The nature and scope of the invention having been indicated and a particular embodiment having been described, what is claimed is:

l. A shoe inseam sewing machine having stitch forming devices including a curved hook needle and a looper, a cam shaft for operating the stitch forming devices, two independent actuators for the looper having followers cooperating with cams on the cam shaft, a three-cornered support having three connection arms, one arm of which is slidably mounted in the machine and arranged to carry the looper, and operative balland-socket connections between the actuators and the other arms of the support for moving bodily and guiding the looper while laying the thread in the hook of the needle, in combination with a separate link comprising one of the connections interposed between one of the actuators and the support to prevent foreshortening movement of the support from causing undue frictional force to be applied to the actuators.

2. A shoe inseam sewing machine having stitch forming devices including a curved hook needle and a looper, a cam shaft for operating the stitch forming devices, two independent swinging actuator arms for the looper mounted for movement in two spaced planes, followers on the actuator arms cooperating with cams on the cam shaft, a three-cornered support having three connection arms and defining a plane at right angles to the planes of th actuator arms, one arm of which support is slidably mounted in the machine and is arranged to carry the looper, and operative ball-and-socket connections between the actuator arms and the support for moving bodily and guiding the looper while laying the thread in the hook of the needle, in combination with a separate link comprising one of the connections interposed between one of the actuator arms and the support to prevent foreshortening movement of the support from causing undue frictional force to be applied to the actuator arms, and a hinge pin joint between the link and the support having bearing surfaces extending in the same general plan with the support to prevent displacement of the support from its plane.

FRED C'. EASTMAN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,543,265 Morrill June 23, 1925 1,971,575 Morrill Aug. 28, 1934

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