US2420697A

US2420697A - Sewing machine

Info

Publication number: US2420697A
Application number: US600126A
Authority: US
Inventors: Clarence S Best
Original assignee: NAT SEWING MACHINE CO
Current assignee: NAT SEWING MACHINE CO; NATIONAL SEWING MACHINE Co
Priority date: 1945-06-18
Filing date: 1945-06-18
Publication date: 1947-05-20
Anticipated expiration: 1964-05-20

Description

C. 8. BEST SEWING MACHINE May 20, 1947.

2 sheets-sheet 1 Filed June 18, 1945 INVENTOR.

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c. s. BEST SEWING MACHINE Filed June 18, 1945 2 Sheets-Sheet 2 .INVENTOR. w dfiwi and presser foot Patented May 20, 1947 SEWING MACHINE Clarence s. Best, Belvidere, 111.,

National Sewing Machine Company,

assignor to Belvidere,

111., a corporation of Illinois Application June 18, 1945, Serial No. 600,126

7 Claims.

in one direction and then reverse the direction of sewing by manipulating control means provided for that purpose.

For certain kinds of work, particularly for mending and darning, it is desirable to sew back and forth, that is, to reverse the direction of sewing frequently, and for this purpose it is convenient to be able to manipulate the cloth manually, alternately toward and away from the operator, without the necessity of operating reversing control means.

I accomplish the desired result by providing means for dropping the feed dog below its normal position in the bed plate, so as to be out of contact with the work, thus permitting the cloth to be manipulated by the operator in desired directions without reversing the direction of movement of the feed dog.

By my invention, I have devised simple and eflicient mechanism for dropping for easily restoring it to normal position.

In the drawings:

Fig. 1 is an elevational view of a sewing machine embodying my invention.

Fig. 2 is a bottom plan view, on an enlarged scale as compared with Fig. 1, taken in the plane of the line 22 of Fig. 1, looking in the direction indicated by the arrows.

Fig. 3 is a transverse, vertical sectional view, taken in the plane of the lines 3-3 of Fig. l and 3-3 of Fig. 2, looking in the direction indicated by the arrows.

Fig. 4 is an enlarged fragmentary sectional View, taken in the plane of the line 4-4 of Fig. 3, looking in the direction indicated by the arrows.

Conventional sewing machine parts, shown in the drawings, comprise the bed plate H1, upright standard ll, overhanging arm [2, sewing head l3 It. On the upright standard I! is a turn button l5 for controlling the drop feed mechanism of my invention. In Fig. 1, dotted lines indicate the conventional main drive shaft it for operating the needle bar, and a vertical crank drive connecting rod ll for actuating the the feed dog and hook shaft l8 beneath the bed plate Ill. The feed shaft is indicated at l9.

The hook shaft i8 is rotatably mounted in bearings 2b, and is operatively connected to the power shaft It through a crank 2i and crank pin 22 mounted on the end 23 of the connecting rod ll. At the opposite end, the hook shaft 18 carries the hook, race and bobbin indicated as a whole by the numeral 24.

The feed shaft l9 is a rock shaft the function of which is to impart reciprocating movements to the feed dog 25 in horizontal planes. Said shaft I9 is operatively connected to the feed dog through the following mechanism: a feed rocker 25 fixedly mounted on the shaft I9, a short shaft 21, and a feed, block fork 28 on which is mounted the feed dog 25 as indicated at 29 (Fig. 3). At its other end, the feed shaft I9 is mounted in a bearing 30, and is operatively connected with power means (not shown) for imparting rocking motion to said shaft l9 through the bifurcated member 3|, link 32, pivot pin 33 and link 3G. The link 32 carries the roller 35 which travels inthe slot 35 of the reversing bracket 31 which is pivotally connected to the bed plate [0 or other fixed part of the machine in such manner that the position of the bracket and the angle of the slot 36 may be altered, as will be explained hereinafter.

As is well understood in the art, the rotatable shaft 18 rotates the hook 24 which carries the bobbin and cooperates with the needle in the stitch forming operation, while the rock shaft l9 imparts a reciprocating feed and return or push and pull motion to the feed dog 25 for moving the cloth away from the operator in conventional sewing, or toward the operator in reverse sewing, depending on the adjustment of the reversing bracket 3?. The feed dog 25 must be in raised or cloth-engaging position during the push stroke and it must be in lowered position, out of engagement with the cloth, during the pull stroke of the reciprocating motion.

This rise and fall action of the feed dog is accomplished by means of a clutch-cam 38 slidable longitudinally on the shaft I'll. The clutch-cam 38 consists of an eccentric member and an adjacent concentric portion, the latter being provided with a pair of. square edged ribs 39 which provide between them a groove d0 rectangular in cross section, adapted to be engaged by a clutch-cam shifting fork M connected rigidly to the end 42 of a longitudinally extending rod 43. The rod a3 is actuated by the control button l5 through a link 44 connected to a pin 45 in the block 45 which is fixedly mounted on the rod 43.

When the rod 43 has been actuated by the control button P5, to move the fork 4| and clutchcam 38 to the left, as in Fig. 2, a notch 41 in the cam adjacent the hook 24 engages a pin 48 on the shank of the hook 24, and causes the clutchcam 38 to be rotated with the hook and thereby to produce the rise and fall of the feed dog 25, due to the engagement of the clutch cam 38 with the arm's'ofthe feed block fork 28,'as best shown in Figs. 2 and 3. When the rod 43 has been actuated toward the right, as indicated in Fig. 4, a recess 49 in the clutch-cam 38 and a pin 50 which projects from the bearing '20 come into register with each other and thus the clutch-cam 38 is disengaged from the shaft "f3 --and re'tained in a non-rotating position where it holds the feed block fork 28 in its lowermost position, and-consequently holds the feed dog 25 in dropped position below the surface of the bed plate H1 and out of engagement with the cloth.

Theshaft l-9 continues to'impart'the push and pull motion to the feed dog, but since the clutchcam 38 is being held stationary relatively to the shaft 18 by reason of the'engagement of the recess '49 and pin '58, and the clutch-cam 38 is in -a position whereitfdepresses the fork '28 and consequently the feed dog 25, the cloth may be manipulated by the operator, back and forth, as

required for mending and darning, Without utilizing reversing means for that purpose. The reversing'bracket 37 is provided with connections 51 leading to manually controlled means (not shown) for actuating the bracket 3! to 'set the machine for either regular or reverse sewing. However, when the drop feed mechanism of my invention is employed for the purpose'of'dropping the feed dog to inoperative position, it is immaterial whetherthe reversing mechanism is in one position or another, because the operator is able manually-to move thecloth back and "forth without interference by the feed dog and regardless of its direction of movement.

Changes :may beina'de in details of construction without departing from the scope ofmy invention as set forth in the appended claims.

I claim:

1. A sewing machine provided withdrop 'feed mechanism comprising a rotatable hook shaft, a

bed plate, a feed 'dog movable in the bed plate, a rock-shaft journaled under the bed plate, ope'rative connections between the rock shaft and the feed dog for imparting reciprocating feed and return motions to the feed dog, means for rocking s'a'id rock shaft, a clutch-cam slidably mounted on the hook shaft, manually controlled 5 means for slidably moving said clutch-cam on "the hook shaft, 'cooperatingmea'nson the clutchcam and hook shaft for causing the clutch-cam 'to rotate with the hook shaft when the clutchcam been moved to a predetermined position on said hook shaft, and means for holding the clutch-cam against rotation when the "clutchcam has been moved to another predetermined position on said hook shaft, said operative connections between the rock sha'ftand the -feed dog for imparting reciprocating feed and return motions to the feed dog including 'a pivotally mounted member which engages the clutch-cam and imparts to the "feed dog .rise and fall movements while the clutch-cam rotates with the hook shaft and "which holds the feeddog'in dropped position while the clutch cam is non-rotating.

12. The dro feed mechanism defined by claim 1, in which the cooperating means on the clutchcam and hook shaft for causing the clutch-cam bearing and clutch-cam.

I i. The drop feed mechanism defined by claim 1, in which the manually controlled means for slidably moving'the clutch-cam on the hook shaft fcoinprises a rod parallel with the hook shaft and longitudinally movable relatively thereto, an eX- tension arm on the rod at right angles thereto engaging said clutch-cam, and a manually operable lever for shifting the rod.

5. A sewing machine provided with drop feed mechanism comprising a rotatable hook'shaft, a bed plate, a feed dog movable in the bed plate, a rock shaft journaled under the bed plate, operative connections between the rock shaft and the feed dog for imparting reciprocating feed and return motions to the feed dog, means for rockme said rock shaft, a clutch-cam slidably mounted on the hook shaft, manually controlled means for slidably moving said clutch-cam on the hook shaft'cooperating means on the clutch-cam and hook shaft for causing the clutch-cam to rotate with the hook shaft when the clutch-cam has been moved to a predetermined position on said hook shaft, and means for holding the clutchcam against rotation when the clutch-cam has been moved to another predetermined position on said hook shaft, said operative connections between the rock shaft and the feed dog for imparting reciprocating feed and return motions -to the feed dog including a pivotally mounted forked member which engages the cam portion of the clutch-cam and is raised and lowered by the rotation of the clutch-cam when the latter is being rotated with the hook shaft and remains in its lowermost position while thec'lutch-cain is non-rotating.

6. 'A sewing machine provided with drop feed "mechanism comprising a rotatable 'hook shaft, a bed plate, a feed dog movable in the bed :plate, 'a rock shaft journaled under the bed plate, 'operative connections between the rock shaft and the feed dog for imparting "reciprocating feed and return motions to th feed dog, means for rocking said rock shaft, means for imparting rise'a nd fall motions to the feed dog including a cam member slidably mounted on the hook shaft, manually controlled means for moving said slid- -ab'le cam member on the hook shaft, means for causing said slidable cam member to rotate with the hook shaft when it has been moved to a pre- -'determined position "on said hook shaft, and means for rendering said slidab'le 'cam member non-rotative and thereby holding the feed dog in lowered non-rising position when the slidable member has been moved to another predetermined position on the hook shaft, said operative connections between the rocksh'aft and the feed dog for imparting feed and return motion to the feed dog including means engaging said 'slidable cam member on the hook "shaft 'for'imparting 'rise and fall motions to the feed dog.

7. The drop feed mechanism defined by claim 6, in which the manually controlled means for 'moving said slidable cam member on the hook shaft comprises a rod longitudinally movable be- 5 6 neath the bed plate a nd a lever accesslble above UNITED STATES PATENTS the bed plate for movmg sa1d rod.

CLARENCE S. BEST. Number Name Date 436,321 Stirckler Sept. 9, 1890 REFERENCES CITED 1,879,191 Goosman Sept. 27, 1932 The following references are of record in the Gneb May 1933 file of this patent:

Hohmann Jan. 24, 1939