US2671421A - Device for changing the stitching direction of sewing machines - Google Patents

Description

March 9, 1954 2,671,421

W. HEIMANN DEVICE FOR CHANGING THE STITCHING DIRECTION OF' SEWING MACHINES 4 Sheetsf-Sheet l Filed March 14, 1952 FIM-w March 9, 1954 W, ||E|MANN A 2,671,421

DEVICE FOR CHANGING THE STITCHING DIRECTION OF SEWING MACHINES Filed March 14, 1952 4 Sheets-Sheet 2 March 9, 1954 w, HElMANN 2,671,421

DEVICE FOR CHANGING THE STITCHING DIRECTION OF SEWING MACHINES Filed Ma-IGh 14, 1952 4 Sheets-Sheet 3 I WiL/#El AfA N/V March 9, 1954 w, HElMANN l 2,671,421

DEVICE FOR CHANGING THE STITCHING DIRECTION OF SEWING MACHINES Filed March 14, 1952 4 Sheets-Sheet 4 [IHIIIIIIIIIIIIIIH wma INVIA/m?.-

Patented Mar. 9, l954 DEVICE FOR CHANGING THE S-TITCHING DIRECTION OF SEWYING MACHINES Willi Heimann, Kaiserslautern, Pfalz, Germany,

assignor to G. M. Pfaff A.G., Kaiserslautern, Pfalz, Germany, a corporation of Germany Application March 14, 1952, Serial No. 276,586

3 Claims. l

This invention relates to a device for changing the stitching direction of sewing machines.

In the hitherto customary sewing machines, the change or the reversal of the stitchingl direction is often eiiected by a manually operable lever mechanism. Consequently, this reversal from the forward to the backward stitching direction and vice versa necessitates the removal of one and generally of the right hand of the operator from the goods.

During the interval, the goods are only controlled by one hand; the result is uneven stitchings and seams.

As a consequence thereof, the machine operators prefer to interrupt the sewing work altogether during the change or reversal of the stitching direction, which causes work interruptions and idle periods.

It is the main object of the invention to eliminate this serious drawback and to enable the handling of the work pieces with both hands during the stitching reversal periods.

It is also an object of the invention to eliminate interruptions of the sewing work and to thereby improve its economy.

With these objects in view, a pressure operable member is provided within easy reach of the one lower arm of the machine operator; upon pressing upon this member by means of the lower arm of the operator and without any change of its position, the stitching direction is changed; upon release of the pressure member, the change of the stitching direction is automatically effected into the opposite direction.

In accordance with a preferred embodiment of the invention a separate plate-shaped knob is located in the machine table which may be pressed down by the operator without changing the position of his arm and without lifting it from the operating position.

This pressure operable member is by means of a pivotable lever operatively connected with a shaft, which is rotated upon down pressure of said member. The rotation of the shaft is transmitted to the mechanism, which is used to change or reverse the stitching direction.

This arrangement enables the handling of the work piece with both hands of the operator during every stage of the Work. The obtainment of straight and neat stitchings and seams is thereby secured.

In conformity with a further embodiment of the invention, a customary manually operable device for the reversal of the stitching direction is provided.

CFI

The invention will now be described more in detail and with reference to the accompanying drawing showing a preferred embodiment thereof, without however in any way restricting the invention to the same.

In the drawings:

Fig. 1 shows a vertical sectional view of the machine on line I-I of Fig. 2;

Fig. 2 shows a side view thereof;

Fig. 3 is a plan view;

Fig. 4 is a large-scale fragmentary sectional view, similar to Fig. 1, illustrating the reversing elements;

Fig. 5 is a large-scale fragmentary front elevational view of the elements shown in Fig.4, partly in section; and

Fig. 6 is a large-scale fragmentary top view thereof, party in section. f

The drawings show the machine in the position for advance stitching work. The change to another stitching direction is performed, as follows.

The sewing machine is provided with a plateshaped pressure member 2, which is inserted into the machine table I. The pressure member is connected to the one end of a lever 3, which is swingably supported on shaft 6.

If the operator presses down plate 2 with his lower arm, a swinging movement is imparted to shaft S, which is supported by bearings 4, 5. An oscillating arm 'I is solidly connected to shaft 6. Upon downward pressure of member 2 a rod 9, pivotally connected to arm 1 at 8, is displaced in an upward direction. Rod 9 is operatively connected to a plate II) which is adapted to change the stitching direction; the plate I0 is supported in the machine head I I by means of a hinged screw I 2, which oscillates about its axis. By this oscillating movement, the position of the plate member I6, which is connected at I3 with plate I9 and at I5 with excenter push rod I4, is changed, whereby the rear stitching position is established.

If the operator removes his lower armfrom pressure plate 2, spring I'I which by means of a pin I8 is suspended from rod 9 and is connected to base plate I9, pulls plate III into the advance stitching position.

A handle 20 is provided which may be operatively connected to plate I 0 in order to effect manually the reversal of the stitching direction in the usual manner.

In Fig. 4 there are illustrated the reversing elements, in position for forward stitching which comprise the rod 9, the plate I0, the hinge screw I2 that carries the handle 20, the plate member I 6 which is connected at I3 to the plate I0, as well as the eccentric push rod I4 that is connected at I5 to the plate I0.

The push rod I4 is provided with a bifurcation 22 that has two oppositely disposed parallel cam follower guides 23. Between these guides there rotates in abutment therewith a cam 2| that is eccentrically secured on a main shaft 24 (Figs. 4 and 5) of the sewing machine head I I (Fig. l) for rotation therewith.

Rotation of the shaft 24 will cause rotation of the cam 2I which, in turn, will cause reciprocating rocking of the push rod I4. Owing to the connection of the push rod I4 to the plate member IB at I5, and the pivot connection of said member It to the plate I8 at I3, the rod I4 will move reciprocally vertically. This up-and-down movement of the rod I4 is transmitted to the feed machinery connected at the underside of the machine table I, as best shown in Fig. 1 (see the s 'ment of the rod 9 will cause the plate I9 to be swung about the axis of the screw l2 (Figs. 1. 2, 5 and 6) from the position "a for forward stitching (Fig. 4) to the rearward stitching position schematically indicated at b; at the same time, the pivot point I3 will be moved about the axis of the screw I2 from c to 61. By this shifting, the plate member IS will change its position relative to the rod I4 so that thereafter the rod I4 will transmit its reciprocable movement to the feed machinery in such a manner as to cause reverse stitching.

Since certain changes may be made in the above article and different embodiments of the invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in d. the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

Having thus described the invention, what I claim as new and desire to be secured by Letters Patent, is as follows:

1. A device for the control of the stitching direction in table provided sewing machines, comprising a plate-shaped pressure operable control member vertically movably located in an upward and downward direction in the machine table within the reachof the lower arm of the machine operator, mechanisms including a plate adapted to establish the forward and rearward stitching direction, a shaft supported at the underside of said table,`a double arm lever swingably supported by said shaft, the one arm of said lever being connected to said pressure member, means to transmit the vertical up and down displacement of said control member to the other arm of said lever and a vertically displaceably rod connecting said lever arm to said stitch changing plate.

2. In a device according to claim l, a spring partially surrounding said vertically displaceable rod being fastened with its upper end to said rod and with its lower to said machine table and adapted to upwardly pull the pressure member carrying arm of said swingable double arm lever.

3. In combination with the device according to claim 2, a manually operable lever connected to the plate to establish the forward and rearward stitching direction.

WILLI HEIMANN.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 1,257,900 McCollum Feb. 26, 1918 2,053,757 Woodward et al Sept. 8, 1936 FOREIGN PATENTS Number Country Date 416,234 Great Britain Sept. 13, 1934

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