US1693524A - Feeding mechanism for sewing machines - Google Patents

Description

NM), 27, 319289 I 1,693,524

- R. MUNDLQS FEEDING MECHANISM FOR SEWING MAGHIEE S Filed Jan. 26, 1927 Patented Nov. 27, 1928.

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RUDOLF MUNDLOS, OF MAGDEBURG, GERMANY.

FEEDING MECHANISM FOR SEWING IVIAGHII Q'ES.

Application filed J'anuary.26, 1927, Serial No. 168,756, and in Germany April 29, 1925.

This invention relates to feeding mechanism for sewing machines by means of which either usual stitches or zig-zag lines of stitches can be made, i. e. in which the material feeder executes a movement in the longitudinal direction of the machine, a movement transversely to the first movement,

. and a reciprocating movement in vertical direction.

The invention has for its object to improve the driving mechanism for the materialfeeder for such machines and to provide a sewing machine of such construction that the samewill be capable in operation to make stitching which may be either of the zig-zag type or'straight stitches.

The means for actuating the material feeder includes .an oscillating member or link which transmits its. movement by 2. connect-.

ing rod 11 upon a frame-shaped slide 12, with which the material feeder 20 is connected. The oscillating shaft 18 has arms which carry an oscillating bolt 16. This oscillating bolt 16 is connected to the frameshaped slide 12 and the material-feeder 20 is fixed on the same. By the movement of the frame-shaped slide a longitudinal movement is imparted to the material-feeder, a transverse movement being imparted to the same by the oscillating of the shaft 18.

In this form of construction the number of moving parts are reduced to a minimum. It presents further the advantage that, when the frame-shaped slide 12 is locked in one of its positions, the machine can be used for usual stitching. Special means are provided to hold the frame-shape slide in the most convenient position for stitching, as will be hereinafter explained with reference tt};the

. figures of theaccompanying drawings in which Fig. 1 shows a rear elevation of the machine and Fig. 2 is a plan view seen from below, The main shaft 1 is journaled in bearings 2 and 3 which are fixed on the machine frame. On this main shaft is secured a pinion 4 which meshes with a spur wheel 6 held in a bearing 5. Rigid with this spur wheel 6 is a cam disk 7 which guides a stud 9 of a lever 10. This lever 10 ispivoted upon a bolt 8 and is given an oscillating movement when the stud 9 is moved by the cam which is attached to the spur wheel 6. One end 11 of a connecting rod is secured in a curved slot of the lever 10. This connecting rod is composed of two parts 11 and 11 which slide one into the other and held together by the action of a spring 11 The part 11 of the connecting rod is pivotally mounted on the frame-shaped slide 12, and by adjustmg the rod 11 in the lever 10 the amplitude ofthe movement of the frame-shaped slide 12 is regulated. The frame shaped slide 12 engages guides 13, and it has a roller 14 over which is located a fork -15. This fork 15 is mounted on an oscillatable bolt 16 carrled by two arms 17 which project from an oscillatable shaft 18. This shaft 18 is journaled at its ends on points 18*. The oscillatable bolt 16 carries, besides the fork 15, a holder 19 of a material-feeder 20.

The reciprocating movement of the frameshaped slide 12 is transferred by the fork 15 and by the holder 19 to the'material-feeder' 20, at the same time that a movement transversely to the longitudinal direction of the machine is communicated to said materialfeeder by the oscillating movement of shaft 18 and consequently of the arms 17 and of the bolt 16. The lifting movement of the material-feeder is controlled by a cam 21 on the main shaft 1 and by the oscillating shaft 18 to which it is connected, in a well known manner, and is driven from the main shaft 1 by-a lever system which acts upon a lever or arm 22 on said shaft 18.

When the machine has to be used for straight stitching, a guide frame 25 is mounted on the machine frame as shown in Figs. 1 and 2,-which. guide frame has a curved portion 26. The part 11 of the connecting rod, facing the frame-shaped slide carries, between the frame-shaped slide 12and the lever 10 on its upper side an abutment pin 27 which, in certain positions,

strikes against the curved portion 26 of guide 25 to which is pivoted a lever 28- which may be operated by the knee of a person using themachine through the intermedia of a depending knee lever 31, its elbow lever 30 and a connecting rod 29, equivalent means may be used to move the lever 28 into'and out of engagement with the slidable frame The mechanism described serves in part w for straight or ordinary back stitching, and

it operates in the following manner: en the edge of the goods has been folded, and thread used for stitching is adjacent to the outer edge of the seam, the material-feeder 20, or the frame-shaped slide 12, has to be brought into the outer dead center position.

This is eifected b the knee actuated lever 31 which, through t e intermediary of the lever system 30, 29, 28,.pushes the frame-shaped slide 12 into its extreme right hand dead center position. At this movement of the frame-shaped slide 12the part 11 of the connecting rod is pulled away from part 11, in opposition to the action of spring 11 neither the lever 1-0 nor the cam -7 being impeded as to their oscillating or rotating movements.- 1 V The length of the stitches depends on the stroke of the frame-shaped slide 12 and this stroke depends on the position of the connecting rod'11 with the lever 10 and the position of the adjustable stud pin or oolt which adjustably connects the end of the rod 11 withthe slotted lever 10. When the rod is in the position shown in Fig. '2, the stroke of the frame-shaped slide is near its limit for producing the longest stitches, and

when the frame-shaped slide 12 is shifted by means of the knee lever 31 it would, owing to the yieldability of the connecting rod 11 be pushed too far in outward direction. In order to prevent this the curved portion 26 of the guide 25' and the abutment pin 27 on part 11 of the connecting rod are provided. The curved portion 26 is constructed so that the'frame-shaped slide can be brought, by meansof the knee operated rod 31, only into an outer extreme position which corresponds to the actual stroke or to the actual position of the connecting rod 11 in the lever 10. r

A sewing machine of the character set forth and illustrated may be used for ordinary sewing by simply moving the bar 11 to the oppositeend of the slot through the lever 10, in which position it may beheld by a clamp bolt the shank of which passes through the slot of the cameactuated lever .10, and when so positioned and held, the

mechanism for producing zigzag stitches will be'inoperative and the machine operates to produce straight stitches.

The stitching mechanism for ordinary straight stitching is not shown, as 'it is of well known construction, being of the rotary shuttle type, and, in connection therewith,

it may be stated that the needle fplate has a transverse slot for the passage 0 the needle and that lateral movement is imparted thereto. The presser foot is" also provided with a slot, as the needle carried by the needle bar and the presser foot are each transversely slitted so that the needle may pass through the same and the work.

I claim:

1. In a sewing machine for moving a material-feeder in longitudinaldirection comprising a main shaft, a material-feeder, a bearing on the main shaft, an oscillatable lever, a frame-shaped slide associated with.

the main bearing and with the materialfeeder, a connecting rod between said lever and material slide, a stud projecting from the slide, an oscillatable bolt on which the material feeder is pivotally mounted, and a ting: on said bolt for engagement with said s 1 e.

- 2.'The combination in a sewing machine having means whereby the stitches 'produced may be either zig-zag or straight, of a cam actuated lever having therein a segmental slot, a sliding frame associated with the cam actuated lever, a two part connecting bar the two parts of which are slidablyconnected, 2; spring attached to each of the .for adjustably attaching one end of said two part connecting bar with the cam .actuated lever.

3. In a sewing machine, the combination of a slide mounted for reciprocation and associated with stitch controlling means, said controlling means comprising a roller carried by said slide, a shaft mounted for oscillation,'a fork which engages the roller, a material feed mounted for movement on the shaft which carries said fork, a main shaft, a cam thereon for actuating the material feed, and means driven from the main shaft and connected. with the slide by means of which the material feed can be set and actuated for either straight or zig-zag stitches. a

41. In a sewing machine having means for producing either straight or z igzag stitches, Y

a frame-shaped slide mounted for reciprocation at right angles to the direction of the material feed, manually adjustable mdans comprising a lever which'is adapted to restrict movement of the slide by engagement therewith, a main drive" shaft having thereon means for actuation of a material feed and a cam disk, anv oscillatory lever which engages the cam disk, a two part connecting rod, one of the parts thereof being adjustably connected to the lever and the other part pivotally connected to the slide, and a spring eonnectin the two partsof the connecting rod toget er.

5. The combination in a sewing machine of the zigzag stitch type, of a main rotary shaft, a rock shaft, a material feed operated in part by both of the aforesaid mentioned ing aIp rojecting stud, a fixed frame with which the stud may be positioned to engage a portion of the said fixed frame and thereby 10 control movement of the slide.

In testimony whereof I afiix my signature.

RUDOLF MUN DLOS.

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