US2652797A - Mechanism for disconnecting and reinserting the lifting movement of the cloth feed claw in sewing machines - Google Patents

Description

Sept. 22, 1953' GIAMMAN MECHANISM FOR DISCONNECTING AND REINSERTlNG THE LIFTING MOVEMENT OF THE CLOTH FEED CLAW IN SEWING MACHINES Filed March 28, 1951 I nventor A N GZAMM By I i I 2 I Attorneys Patented Sept. 22, 1953 MECHANISM FORDISCONNECTING- AND BE.

INSERTING' THE LIFTING- MOVEMENT OF THE CLOTH FEED CLAW IN SEWING MA- GHINES Giuseppe Amman, Milan, Italy, assignor to Fratelli Borletti Societa per Azioni, Milan, Italy,

a body corporate Application March 28, 1951, Serial No. 217,932 In Italy April 7, 1950 2 Claims.

centric engaged in the fork the lifting of the dog by means of a pin therewith connected and penetrating into a slot of said dog, being mounted on an axially slidable bar, which may be displaced forward or backwards by means of a lever that can be operated by the operator, in such a way that, when the bar is pulled in one direction, the pin connected to the forked lever, following the latter, comes out of the opening in the dog, and penetrates again into said opening when the bar is pushed in the opposite direction.

Said mechanism is simple and practical, and is particularly adapted to be used in connection with machines in which the eccentric operating the forked lever is arranged with its relative shaft underneath the base plate.

Further particulars and advantages of the object of the invention will appear from an embodiment thereof illustrated in the annexed drawing, in which:

Fig. 1 shows in perspective view the assembly of the mechanism as applied to a sewing machine;

Fig. 2 is a perspective view of a part of the mechanism, separated into its elements in order that its construction and working will be better understood.

Bar I is slidably mounted within supports 2 and 3 integral with the base of the machine. An appendage 5, fastened rigidly to said bar, is held in a fork 6 forming an extremity of lever 1 pivoted at 8.

At the other end of bar I is loosely mounted lever 9 having a pin shaped appendage I9.

On the hub of lever 9 is mounted hub II of fork I 2. Said hub is connected to the hub of lever 9 by means of a screw I3, or any other equivalent member, in such a way that the position of shaft l0 relative to fork I2 may be adjusted at will, in

order to give dog I4 the right height.

Levers 9 and. I0 and consequently fork III2 are prevented from sliding along bar I by suitable stop washers I5, which, while preventing axial displacements relative to bar I, do not prevent tip, re-enters opening 2 rotations in respect to said bar of said lever 9-l 0 and consequently of fork I I-I 2.

Bar l is prevented from turning by fork 6, or by any other suitable member, a key or a screw; for instance, entering a longitudinal groove or keyway of said bar.

Pin "1- enters into an opening I I cut in the support of the dog.

Fork I2 embraces a rotating or oscillating eccentric IB, from which it is given the reciprocating up and down movement.

From the foregoing the operation of the mechanism is easily understandable.

Eccentric I8 during its rotation transmits a motion to fork I2 which transmits it to pin [0 that, in its turn, transmits it to dog I4; this occurs when lever I is fully displaced to the right. When, on the contrary, lever 1 is fully displaced to the left, bar Iv slides toward the right as per arrow I9 and fork I2 slides on eccentric l8, sufficiently long as not to lose contact with the same.

In this displacement pin I0 comes out of opening I I, thus leaving the support of the dog, which thus remains in a low position and is no more effected by the up and down movements of fork l2 and pin Ill. In the inverted movement of lever 'l the extremity of pin I0, which is conical at its I1, and communicates again said movements to dog M.

It is understood that the constructive particulars of the mechanism may be made different from those represented in the drawings and above described, the mechanism itself still remaining-at all times within the range of the invention.

What I claim is:

1. A mechanism for lifting the feed dog of a feeder in a sewing machine comprising a shaft, means mounting the shaft for axial slidable movement, a lever freely rockably mounted on the shaft, means for securing the lever on the shaft against axial movement relative to the shaft, said lever having a bifurcated end, an elongated cam rotatably mounted with its axis parallel to the shaft and embraced by the bifurcations of said lever for imparting rocking movement to said lever, a pin carried by said lever and spaced from said shaft and engageable with said feed dog to impart up and down movement to the dog, and means for axially shifting the shaft to displace the lever axially along its cam and to shift the pin into and out of driving engagement with the dog.

2. A mechanism for lifting the feed dog of a feeder in a sewing machine comprising a shaft,

means mounting the shaft for axially slidable movement, a crank lever having a hub freely rockably mounted on the shaft, means for securing the lever hub on the shaft against axial movement relative to th shaft, a cam follower lever mounted on the hub of the crank lever, means for adjustably fixing the cam follower lever on the hub of the crank lever, said cam follower lever having a bifurcated end, an elongated cam rotatably mounted with its axis parallel to the shaft and embraced by the bifurcations of said lever for imparting rocking movement to said levers about said shaft, a pin carried by the crank lever and spaced from the shaft and engageable with said feed dog to impart up and down movement to the dog, and means for axially 4 shifting the shaft to displace the cam follower lever axially along the cam and to shift the pin carried by the crank lever into and out of engagement with the dog.

GIUSEPPE AMMAN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,144,802 Hohmann Jan. 24, 1939 FOREIGN PATENTS Number Country Date 108,911 Switzerland Feb. 16, 1925 298,049 Great Britain Oct. 4, 1928

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