US2693778A

US2693778A - Embroidering mechanism for zigzag sewing machines

Info

Publication number: US2693778A
Application number: US292468A
Authority: US
Inventors: Harris Carl
Original assignee: Individual
Current assignee: Individual
Priority date: 1952-06-06
Filing date: 1952-06-09
Publication date: 1954-11-09
Anticipated expiration: 1971-11-09

Description

Nov. 9, 1954 c. HARRIS 2,693,773

EMBROIDERING MECHANISM FOR ZIGZAG SEWING MACHINES Filed June 9. 1952 4 Shees$heet l INVENTOR. Carl Harris Wcrney C. HARRIS Nov. 9, 1954 EMBROIDERING MECHANISM FOR ZIGZAG SEWING MACHINES 4 Sheets-Sheet 2 Filed June 9. 1952 INVENTOR. Carl Harris cnmss C. HARRiS Nov. 9, 1954 EMBROIDERING MECHANISM FOR ZIGZAG SEWING MA Filed June 9. 1952 4 Sheets-Sheet 3 6 mwzmox.

Carl Harris BY QZ a/u fl-Ho'rney.

Nov. 9, 1954 c, R s 2,593,778

EMBROIDERING MECHANISM FOR ZIGZAG SEWING MACHINES Filed June 9, 1952 4 Sheets-Sheet 4 Willa/11W I 1. 4 m

' INVENTOR. '5 Carl Harris (4&4 Z M United States Patent EMBROIDERING MECHANISM FOR ZIGZAG SEWING MACHINES Carl Harris, Montreal, Quebec, Canada Application June 9, 1952, Serial No. 292,468 4 Claims. (Cl. 112-158) This invention relates to sewing machines and more particularly to an embroidering mechanism for sewing machines of the zigzag type.

Zigzag sewing machines are well known in the art and many attachments for such machines have been heretofore proposed to simplify and augment the production and convenient adjustment of the mechanism, and which i substantially reduces the skilled attention required by the operator.

The invention will be described with reference to the accompanying drawing in which Figure 1 is a side elevation of a machine embodying the mechanism of the present invention.

Figure 2 is an elevation of the other side of the machine,

Figure 3 is an end elevation, partly in section,

Figure 4 is an end elevation,

Figure 5 is a plan view of one form of design applied to a fabric, and

Figure 6 is a plan view of another form of design.

The sewing machine illustrated is of the usual zigzag type and comprises conventional elements including a main frame having a work-supporting bed-plate 1, on one end of which is mounted the tubular standard 2 having an arm 3 overhanging the bed-plate 1. The head 4 is carried by the free end of the arm 3. The

needle-reciprocating shaft 5 is journalled in the arm 3 f and extends longitudinally thereof. A needle bar 6 carrying a needle 7 is mounted in the head 4 and is connected to the shaft 5 for reciprocation thereby by usual means, not shown. The needle-bar 6 is journalled in a frame 8 which is pivotally mounted on pin 9 in head 4 for lateral swinging movement. Such movement is imparted to the frame 8 and needle-bar 6 by means of a pitman 10 pivoted at one end by screw 11 to frame 8. A split ring 12 mounted on the other end of the pitman embraces an eccentric 13. The eccentric 13 has an enlarged opening 14 therein to receive a transverse shaft 15 journalled in the walls of arm 3. The eccentric 13 is carried by a frame 16 which is adjustably mounted on a disc 17 fixed to shaft 15. A pin 18 mounted in frame 16 has a rounded end portion extending into an axial bore 19 in shaft 15 and it will be appreciated that adjustment of the frame 16 and consequent adjustment of the eccentricity of eccentric 13 is effected by reciprocation of the pin 18, all in the conventional manner.

The shaft 15 is driven from shaft 5 by means of a gear wheel 20 fixed thereto and a worm gear 21 on shaft 5. Shaft 5 is driven in the usual manner by belt pulley 22 mounted on one end thereof.

In accordance with the invention, means are provided for automatically varying the eccentricity of the eccentric 11 in accordance with a fixed preselected pattern and such means, as shown, comprises a spindle 23 reciprocally mounted in bore 19 and having a conical end portion 24 in engagement with pin 18. Spindle 23 1 acts upon pin 18 in the same manner as the conventional 2,693,778 Patented Nov. 9, 1954 "ice manually-actuated regulating spindle and moves in one direction to reciprocate the pin 18 outwardly and in the reverse direction to permit the pin 18 to reciprocate inwardly under the influence of the biasing spring 26 in frame 16. However, spindle 23 of the present invention is spring-biased in such reverse direction by means of a spring on the spindle, such spring being located in an enlarged diameter portion 27 of bore 19. Spindle 23 has a rounded head 28 located exteriorly of the arm 3 on the rearward side of the machine.

Means for automatically reciprocating spindle 23 comprises a selected one of a series of cams 29 mounted on shaft 30 journalled in an auxiliary frame which includes bearings 31 suitably supported in fixed relation on the main frame of the machine. The cams 29 are keyed to the shaft for longitudinal adjustment therealong by means of the keyway 32 and may be locked in desired position on the shaft by set screws 33 or the like. Each cam 29 comprises a plate of predetermined shape, the edge of which constitutes the cam surface. In operation, a preselected one of said cams is locked in position on the shaft 30 with its edge in engagement with the rounded end of spindle 23, which is urged against the cam surface by the spring 25. It will be observed that, on rotation of the cam, the spindle 23 will be subjected to a succession of cycles of reciprocating movements of desired amplitude depending upon the shape of the cam. As will follow from the foregoing description, such movements will result in corresponding variations in the eccentricity of the eccentric 13.

Means for driving the cam shaft 30 at a suitable speed comprises a shaft extension 34 on the end of shaft 5, a worm gear 35 fixed to shaft extension 34, a gear wheel 36 meshing with gear 35 and fixed to a vertically disposed shaft 37 mounted in bearings 38 and 39 carried by hearing brackets 40 and 41 mounted on the standard 2, a worm gear 42 fixed to shaft 37, and a gear wheel 43 fixed to shaft 30. It will be apparent that the ratio of

gears

35, 36, 42 and 43 may be chosen to provide a desired speed of rotation of cam shaft 30. It will be apparent that cam shaft 30 must rotate very slowly and at a very much lower speed than that of shaft 5. While this speed ratio may vary considerably, a satisfactory ratio is one which will result in one revolution of a cam 29 for each 450 reciprocations of the needle, i. e., for each 450 penetrations of the material by the needle. This ratio may, however, vary from 250 to 750 reciprocations to one cam revolution depending upon the shape and length of design desired. The gear 43 shown has 38 teeth and a diameter of 3 /2 inches. The number of teeth on gear 43 may of course vary considerably and a range of 24-60 teeth may be mentioned by way of example. The gear 36 shown has 19 teeth and a diameter of 1% inches. The number of teeth on gear 36 may likewise vary considerably and a range of 15-l9 teeth is mentioned by way of example.

Means may be provided for holding spindle 23 out of cam-engaging position during positioning of the selected cam for operating movement. This means may comprise a rod 44 reciprocatingly mounted in arm 3 and having a depending end portion 45 for engagement with an annular shoulder 46 on spindle 23. A knob 47 on the other end of rod 44 is provided for imparting reciprocating movement to the rod.

The machine is provided with the usual loop-taker and feed dog mechanism, not shown.

In operation, the lines or paths along which an ornamental design is desired to be formed are marked on a piece of fabric as indicated at 48. Thereafter, the operator, having selected a cam corresponding to a desired pattern and locked it in operating position, operates the machine in the usual manner while, however, merely guiding the work along the indicated lines. The automatic variations in the eccentricity of the eccentric 13 will cause the formation of embroidered designs as indi cated, design 49 in Figure 6 being produced by the action of one cam and design 50 in Figure 7 being produced by the action of another cam. Thus, no special skill is required on the part of the operator in the formation of the designs.

Various changes may be made in the structure described without departing from the spirit of the invention as defined in the appended claims. For instance, the cams 29 and camshaft 30 may be mounted on the front of the machine instead of on the back, as shown. In the latter event, the shaft 15, spindle 23, and associated parts will be mounted in reverse position in arm As will be apparent from Figure 3, such reverse mounting will permit use of a shorter spindle 23.

What is claimed is: 1. In combination with a sewing machine having a ing the eccentricity of said eccentric, an embroidering mechanism comprising an auxiliary frame mounted on th main frame, a shaft mounted in the auxiliary frame in face, said spindle having a free end projecting laterally of said main frame, said free end being engageable with said cam surface, a spring engaging said spindle and urging it into engagement with said cam surface, and a chain of gears mounted in said auxiliary frame and positively and constantly drivably connecting said needle bar-resaid needle bar-reciprocating shaft having an extension on one end thereof, said chain of gears 0mprising a worm gear fixed to said extension and drivable with said needle bar-reciprocating shaft, a shaft mounted in said auxiliary frame in right angular relation to said needle bar-reciprocating shaft, a gear on said right angular shaft meshing with said worm gear, a worm gear fixed to said right angular shaft, and a gear on said cam shaft meshing with said second worm gear, said second gear being of greater diameter than said first gear.

In combination with a sewing machine having a main frame, a needle bar, a driven needle bar-reciprocating shaft, a rotary needle bar-vibrating eccentric, and a spindle reciprocally mounted in the frame for adjusting the eccentricity of said eccentric, an embroidering mechanism comprising a spring engaging said spindle and urging the latter laterally outwardly from said frame, said spindle having a free end projecting laterally of said frame, an auxiliary frame mounted on the main frame, a shaft journalled in said auxiliary frame in right angular relation to said spindle, a cam fixed to said lastmentioned shaft and having a cam edge surface engaging said free end of the spindle, and gear means in positive and constant driving connection with said lastmentioned shaft and said needle-bar reciprocating shaft to drive said cam continuously during all relative movements of said needle-bar reciprocating shaft thereby to impart substantially constant reciprocating movement to said spindle.

References Cited in the tile of this patent UNITED STATES PATENTS Number Name Date 1,020,089 Gray Mar. 12, 1912 2,089,551 Hand Aug 10, 1937