US2819695A

US2819695A - Sewing machine attachment

Info

Publication number: US2819695A
Application number: US390495A
Authority: US
Inventors: Wade W Gergen; Granville V Walmsley
Original assignee: GM Pfaff AG
Current assignee: GM Pfaff AG
Priority date: 1953-11-06
Filing date: 1953-11-06
Publication date: 1958-01-14
Anticipated expiration: 1975-01-14
Also published as: DE1000220B; GB753820A; CH325051A

Description

Jan. 14, 1958 w. w. GERGEN arm. 2,819,695

SEWING MACHINE ATTACHMENT Filed Nov. s, 1953 2 Sheets-Sheet 1 INVENTORS WADE W. GERGEN Gagpvmui V. WALMSLEY V flfffl/M fl" Jan. 14, 1958 w. w. GERGEN ETAL 2,819,695

SEWING MACHINE ATTACHMENT Filed Nov. 6, 1953 2 Sheets-Sheet z w I INVENTORS WADE WGERGEN GRANVILLE V. WALMSLEY United States Patent SEWING MACHINE ATTACHMENT Wade W. Gergcn, Wood River, and Granville V.

Walmsley, East Alton, Ill., assignors, by mcsne assignments, to G. M. Pfaif, A. G., Kaiserslautern, Germany, a corporation of West Germany Application November 6, 1953, Serial No. 390,495

3 Claims. ((11. 112-158) This invention pertains to sewing machine mechanisms and more particularly to that type of mechanism in which the needle bar is given a lateral movement so as to make stitches transverse to the direction of feed of the material.

i Certain types of sewing machines are equipped with such a mechanism for making cross stitches, and this mechanism is controlled by a manipulating handle which may be operated to vary the width of the stitch. In this description, the term width of the stitch will be used to refer to its dimension transverse to the direction of feed, as distinguished from the length of the stitch which is measured along the direction of feed, and it may also be adjusted in most machines. A machine having such a cross stitch mechanism with an external stitch width manipulating handle is disclosed in U. S. Patent 2,297,- 197 to Bolter.

An object of this invention is to provide such a machine with automatic means whereby the width of the stitch may be varied automatically in accordance with a given pattern.

Another object is to provide such a mechanism arranged so that the pattern may be changed at will.

Another object is to provide such mechanism in the form of an attachment which may be applied to a machine of standard construction.

In accordance with this invention generally stated, the attachment is mounted on an extra cover-plate which may be mounted on the machine in the place of a closure plate normally mounted to cover an opening provided for access to mechanism in the machine. Said attachment has driving means arranged for engagement with a moving part of the standard sewing mechanism.

A rotary cam is mounted so as to be driven by said driving mechanism. A cam follower operated by said cam is arranged to operate a pivoted lever, the other end of which is connected with the manipulating element provided to vary the width of the stitch. By this arrangement, said manipulating element is moved in accordance with the shape of the cam and as a result, the width of the stitch is increased and decreased according to the pattern laid out on the cam.

A preferred embodiment of this invention is illustrated in the accompanying drawings, in Which- Fig. 1 is a front elevation of a sewing machine of the type mentioned above equipped with an attachment embodying this invention;

I Fig. 2 is a rear view of the same;

Fig. 3 is an enlarged section on line 3-3 of Fig. 2;

Fig. 4 is an enlarged section on line 44 of Fig. 2;

Fig. 5 is a section on line 55 of Fig. 4;

Fig. 6 is a section on line ti-6 of Fig. 5;

Fig. 7 is a view similar to Fig. 4, showing the parts in the position wherein the driving mechanism may be latched to render it inoperative;

Fig. 8 is an enlarged rear view of the attachment shown in Fig. 2; I Fig. 9 is a section on line 99 of Fig. 8;

. 2,819,695 Patented Jan. 14, 1958 Fig. 10 is an enlarged section on line 10 -10 of Fig. 9;

Fig. 11 is an enlarged section on line 11-11 of Fig. 9; and

Fig. 12 is a diagrammatic view illustrating two patterns of stitches which may be produced by the mechanism as shown in Figs. 8 and 9.

The sewing machine illustrated in the drawings is of the make known as the Pfait, at present manufactured by a firm of that name in Germany. As shown in the drawings, the machine proper comprises a base 1 supporting an upright pedestal 2 which in turn supports an overhanging arm 3 carrying a head 4 in which the needle bar 5 operates. The sewing mechanism includes a shaft 6 extending along the interior of the hollow arm 3, which shaft carries an eccentric 7 operating to give an oscillating movement to a forked member 8. Means, not shown, arranged to give the needle bar 5 a laterally oscillating movement, include a device for varying the amplitude of such oscillation, said means being controlled by a manipulating operable member 9. This member 9 may be set to any desired value in accordance with a scale 10 to set the width of the stitch, or it may be moved during the stitching operation to vary the width of the stitch progressively. The mechanism including the cam 7 and the member 8 operates within the hollow arm 3, and said arm is provided with a rear opening 11 provided for access to said mechanism. Normally, a suitable closure, not shown, is provided to close this opening.

In accordance with this invention, a cover plate 12 is provided to close the opening 11, being secured in place by one or more screws 13 or otherwise. This plate forms a support for the mechanism forming the attachment of this invention. Secured to the plate 12 is a bracket 14 upon which is mounted a slide block 15. Mounted to slide in the block 15 is a movable driving member 16 in the form of a square or rectangular bar bent at right angles, as shown in Fig. 9 to form an extension 17. The shank of the bar 16 extends into the intetier of the hollow arm 3 and is provided at its inner end with a roller 18 arranged to engage the oscillating member 8 of the sewing mechanism. A tension spring 19 is connected to the extension 17 and to the plate 12 and operates to maintain the roller 18 in engagement with the member 8 as the latter oscillates. The end of the extension 17 is engaged in a notch in the end of a lever 20 pivoted at 21 on the bracket 14. The notch may be provided with rounded bearing elements 22 so that the lever may rock with respect to the extension 17 and still maintain engagement therewith.

'A second supporting bracket 23 is secured to the plate 12 by soldering, welding or otherwise. The bracket 23 has a horizontal portion 24 in which is journaled an upright stud 25. This stud is formed to have in succession a circular portion 26, a squared portion 27, another larger circular portion 28, and a second squared portion 29. The

squared portions

27 and 29 have their diagonals equal to the diameter of the round portion 28 so that all of these portions will fit through holes of the same size. Mounted in succession on the stud 25, as shown more particularly in Fig. 10, is a control plate 30 swiveled on the rounded portion 26, a ratchet wheel .31 having a square hole fitted on to the squared portion 27, an upper bearing plate 32 fitted to the round portion 28 of the stud and having a vertical flange 33 (Fig. 8)) secured to the plate 12. This provides an upper bearing for the stud, while the flange 24 provides a lower bearing. Mounted on the upper squared portion 29 of the stud is a cam 34 having on its upper face a camslot .35. In assembling these parts, the ratchet wheel 31 is first mounted on the stud at the squared portion 27, the con- Thestud with these parts assembled is then set into its" hole in the bracket 24 and secured by a washer 36 and a screw 37. The upper bearing plate 32 is then assembled on the rounded portion 28, and its flange 33 secured to the plate 12 in any suitable manner, as by screws 38. The cam 34 may then be placed on the squared portion '29 of the stud.

The end of the lever 29 has pivoted thereto at 39 a pawl 40 biased in a clockwise direction (Fig. 9) by a spring 41 and located so as to engage the teeth of the ratchet wheel 31. Accordingly, oscillation of the lever 26 on the pivot 21 will cause the pawl 40 to move the ratchet wheel 31 in a clockwise direction (Fig. 9). A retaining pawl 42 pivoted at 43 on the bracket 24 and biased by a spring 44 retains the ratchet wheel against reverse movement. The control plate 30 has an upturned arcuate guard flange 45 positioned just outside of the teeth of the ratchet wheel 31 as shown in Fig. 9. The plate 36 also has an extension 30a to which is pivoted a clip 46 having secured thereto a wire hook 47. This clip is pivoted on a stud 43 (Fig. ll) swiveled in the extension 30a and held down by a spring 49 so that the clip and the hook may be raised by pressing the stud 48 upward against the pressure of the spring 49. This is topermit adjustment by engaging the downturned end of the hook 47 in one or the other of a series of holes 50 in an extension 24a of the bracket 24. It will be seen that by this arrangement, the guard 45 is positioned in the path of the pawl 40 in such a way as to prevent its engagement with the teeth of the ratchet wheel until it has reached the upper edge of the guard 45 whereupon it passes over that edge to engage the teeth in a predetermined position, and that position is determined by the setting of the hook 47 in one or the other of the holes 50. In this way, the operation of the ratchet wheel 31 by the pawl 40 may be limited to one, two or three teeth per stroke, according to the setting of the hook 47. This, of course, varies the speed of the ratchet wheel relative to that of the sewing mechanism.

The cam slot 35 is engaged by a cam follower 51 in the form of a screw having a reduced end suitably fitting into the slot 35 as shown in Fig. 10. The cam follower is mounted in the upper horizontal arm 52 of a bent lever by being screwed into a threaded hole in said arm and secured in adjusting position by a lock nut 53. The arm 52 forms part of a lever having a vertical portion 54 and a lower horizontal portion 55 pivoted at 56 to a lower horizontal extension 57 of the bracket 24. While this is, in effect, one lever, it is made in separate parts to permit relative movement. A downward extension 58 of the arm 52 is formed with side flanges 59 forming a channel into which the upturned arm 54 is fitted. A stud 60 secured to the arm 54 extends through a slot 61 in the portion 58. A second stud 62 movable in a perforation in the arm 54 has a reduced end 63 extending into a lower perforation in the arm 58, as shown in Fig. 3. A flat spring 64 held by the stud 60 has an end notch 65 fitting over a reduced neck of the stud 62, as shown in Fig. 3. The stud 62 has an enlarged head 66 by which it may be grasped to pull the end 63 out of the hole in the member 58 so as to permit that member to be moved upward, as indicated in broken lines in Fig. 8, so as to free the cam follower 52 from the cam slot 35 and to permit change of cams.

The horizontal arm 55 of the lever extends underneath the arm 3 of the machine and is provided at its other end with a screw stud 67 provided at its end with a ball pivot 68 which is engaged in a recess 69 in the manipulating member 9. The ball 68 may be disengaged by simply screwing the stud 67 down in the arm 55.

.In the operation of this device, the hook 47 is set into the desired hole 50 so as to limit the movement of the ratchet wheel to one, two or three teeth per stroke, as desired. Then when the sewing mechanism is operated, the oscillation of the member 8 will cause the bar 16 to slide back and forth in the block 15. By this movement, the extension 17 operates to oscillate the lever 20 on its pivot 21. During that oscillation, the pawl 40 engages the teeth of the ratchet wheel 31 at each upstroke of the pawl, and advances the ratchet wheel in amount corresponding to one, two or three teeth, according to the setting of the book 47. After each forward stroke, the pawl 42 engages behind one of the teeth of the ratchet wheel to retain said wheel against reverse movement during the downstroke of the pawl 40. At the end of said downstroke, the tip of the pawl 40 rides up on the guard plate 45. On the succeeding forward stroke, it rides back on said plate, dropping over the upper edge thereof into engagement with the ratchet wheel.

The rotation of the ratchet wheel causes the cam 34 to rotate therewith. During this movement, the follower 51 following the cam slot 35 will be caused to move back and forth slowly, or faster according to the speed of revolution of the ratchet wheel. This movement of the follower rocks the lever 55 on its pivot 56. This causes the stud 67 to swing the member 9 back and forth in accordance with the movement fixed by the cam slot 35. As the member 9 is moved, the width of the stitch is varied. With a cam slot of the heart shape, shown in Fig. 9, a pattern of uniformly changing width is imposed upon the stitches and that pattern may be made short or long. Two such patterns made at different settings of the hook 47 are shown in Fig. 12.

In order to render this mechanism inoperative when other stitching is to be done, the shank 16 of the moving drive member is provided with a cross notch 70 and the block 15 is provided with a headed pin 71 which has mounted therein a cross pin 72 engaged by a fiat spring 73 secured to the block 15. Said block is further provided with a slot 74 adapted to receive the pin 72 when the latter is in proper position. When the mechanism is operating to pattern the stitches, the pin 71 is lifted and turned with the cross pin 72 crosswise of the slot 74 so that the pin 71 will be held clear of the notch 70 and the member 16 may move freely back and forth. When it is desired to put this mechanism out of action, the pin 71 is turned so as to bring the pin 72 into alignment with the slot 74 whereupon the spring 73 will tend to press the pin 71 downward.

When the member 8 has moved the member 16 to the right (Figs. 4 and 7) to a point where the notch 70 is aligned with the pin 71, the latter will drop into said notch, the pin 72 dropping into the slot 74. This engagement of the pin with the notch 70 will hold the member 16 against movement to the left to follow the member 8, and will thus put this mechanism out of action.

It will be seen that this invention provides a simple device which may be made as an attachment to a standard machine, and by which various stitching patterns may be carried out with uniformity and without requiring any special skill by the operator. By providing cams 34 with cam slots of different shapes, a variety of different patterns may be worked out:

Various changes may be made in the details of construction, within the scope of the appended claims, without departing from the spirit of this invention. Parts of the invention may be used without the whole and improvements may be added while retaining some or all of the advantages of the invention.

We claim:

1. In a sewing machine having an overhanging arm, a sewing head carried on said arm, a needle bar mounted in said head, a shaft disposed in said arm operatively connected to said needle bar for vertically reciprocating said needle bar, oscillating means disposed in said arm and operatively connected to said needle bar for oscillating said needle bar laterally to make stitches transverse to the direction of feed, driving means operatively connected to said shaft and to said oscillating means, an oscillating member disposed in said arm operatively connected to said shaft, a rear opening in said arm providing access to said oscillating member, and a control member mounted on the front of said arm operatively connected to said oscillating means and manually rotatable to vary the width of said transverse stitches; the improvement which comprises a cover-plate removably mounted in said rear opening, an aperture in said plate adjacent said oscillating member, a reciprocable driven element slidably mounted on said plate extending through said aperture, resilient means mounted on said plate biasing said driven element into contact with said oscillating member to be reciprocated thereby, cam means rotatably mounted on the rear of said plate, means pivotally mounted intermediate of its end-s to the rear of said plate connected at one end to said driven element and at the other end to said cam to rotate said cam as said driven element is reciprocated, and a lever pivotally connected to said plate, said lever extending beneath said arm engaging said control member at one end and engaging said cam at its other end to be pivoted by rotational movement of said cam and thereby rotate said control member to vary the width of transverse stitches made by said needle bar.

2. The improvement according to claim 1 which further comprises a latch on said driven element operable to hold said driven element out of engagement with said oscillating member.

3. The improvement according to claim 1 in which the connection between said pivotally mounted means and said cam means includes a ratchet wheel connected to said cam means and a pawl for engaging said ratchet wheel connected to said pivotally mounted means.

References Cited in the file of this patent UNITED STATES PATENTS