US2034593A - Feeding mechanism for sewing machines - Google Patents

Description

March 17,1936. H, c NISSEN 2,034,593

FEEDING MECHANISM FOR- SEWING MACHINES Fi led Oct. 4, 1954 s Sheets-Sheet 1 Henry CIfl issen Wi'hweu March 17, 1936. H. c. NISSEN FEEDING MECHANISM FOR SEWING MACHINES $Sheets-Sheet 2 Filed Oct. 4, 1934 116;" a Nisaerp WWW,

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Patented Mar. 17, 1936 UNITED STATES PATENT OFFICE FEEDING MECHANISM FOR SEWING MAC HINES Application October 4, 1934, Serial No. 746,804

.6 Claims.

This invention relates to improvements in feeding mechanisms for sewing machines and has for an object to provide simple means for reversing the direction of feed. Another object of the invention is to provide a four-motion feeding mechanism, adapted to efficiently advance work across the free work-arm of a sewing machine, with means for reversing the direction of feed of the work.

With the above and other objects in view, as will hereinafter appear, the invention comprises the devices, combinations and arrangements of parts hereinafter described in connection with the accompanying drawings which illustrate a preferred embodiment of the invention, from which the several features of the invention and the advantages attained thereby will be readily understood by those skilled in the art.

In the drawings, Fig. 1 is a front side elevation, partly in section, of a sewing machine containing the present improvement, the usual end cap of the work-arm being removed. Fig. '2 is an enlarged bottom plan view of the machine removed from its supporting base, the work-arm being broken away between its ends. Fig. 3 represents a cross section of the machine base taken adjacent to and as viewed in a. direction away from the clip-belt connecting the upper and lower shafts of the sewing machine. Fig. 4 is an end view of the sewing machine work-arm, with the end plate of said work-arm removed and showing the feed rock-shaft journal-pin in section. Fig. 5 illustrates disassembled perspective views of the feed-dog and its carrier. Figs. 6 and 7 are diagrammatical illustrations of feed-dog operations, Fig. :6 illustrating the forward feed and Fig. 7 the reverse feed.

Referring to the drawings, the present inventionhas been embodied in a sewing machine supported upon a hollow base I and having a frame comprising a'bed 2 from which rises the standard 3 of a hollow bracket-arm 4 terminating at its free end in a head 5. The bracket-arm head 5 overhangs the free end of a work-arm;6 extending laterally from the frame bed 2.

Rotatably journaled in the bracket-arm 4 is a horizontally disposed main actuating shaft 7, carrying a belt-pulley 8 and operatively connected to a needle-bar 9, said needle-bar being journaled for vertical reciprocation in the bracket-arm head 5 and carrying a needle I0.

Secured upon the shaft 1 for rotation therewith is a peripherally grooved belt-pulley I 1 connected by a clip-belt l2, within the standard 3, to a similar belt-pulley 13 carried by a short shaft [4 journaled in the machine bed'2 parallel to the main shaft 1. Disposed vertically below and in parallelism with the shaft 14 is a rotary shaft 15 journaled in suitable bearings provided in the bed 2 and the work-arm '6, said shaft 15 carrying a spur-gear 16 in mesh with a driving spur-gear I! carried by the shaft I 4. The driving connections between the shafts I, I4 and I5 are such that said shafts rotate in one-to-one relationship, with the shaft l5 rotating in a direction lower end of a vertically disposed feed-bar 22 to the upper end of which a feed-dog 23 is secured, by a screw-bolt 24, for vertical adjustment of the feed-dog. The feed-dog 23 has the usual serrated work-engaging face and operates through a suitably slotted throat-plate 25 secured upon the work-arm '6, the feed-dog being opposed by any usual or suitable presser-foot 26.

Between the eccentric i8 and the work-engaging face of the feed-dog, the feed-bar 22 carries a stud-pin 2'! pivotally embraced by an apertured end of a controlling member or link 28 of which the apertured opposite end is pivotally secured by a screw 29 upon a crank-arm 30 extending upwardly from one end of a feed-advancing rockshaf-t 3|. thereof carrying the crank-arm 3 0 and isentered by a journal-pin 32 upon a work-arm end-plate 33 removably secured upon the free end of the work-arm 6.

The rock-shaft 31, which is journaled in suitable additional bearings provided in the workarm 6 and frame-bed 2, carries at its inner end a downwardly extending crank-arm '34 to which one end of a link 35 is pivotally secured by a pivot-bolt 36. The other end of the link 35 is connected by a pivot-bolt 31 toa slide-block 38 disposed in an arcuate guideway 39 provided in a rock-lever 40. Intermediate its ends, the rocklever 40 has a hub 4| suitably secured upon a horizontally disposed rock-shaft 42 journaled in a bearing-boss 43 within the frame-bed 2. Mounted upon the pivot-bolt 31 is a connectorplate 44 of which one end is connected to a spring 45 anchored to the arm standard 3, while the 01 116.! end of said plate 44 is connected by a chain The rock-shaft 3| is hollow at the end 46 to a suitable treadle or knee-shift (not shown). Movement of the slide-block 38 in the guideway 39 of the rock-lever, under the action of the spring 45 and in a direction away from the fulcrum-axis of the rock-lever, is limited by a stop-screw 41, and movement of the slide-block in the opposite direction is limited by stop-block 48 which is adjustably secured in said guideway 39 by a screw 49 passing through a slot 5|! provided in the stop-block 4B. The rock-lever 43 is pivotally connected to the lower end of a pitman 5| passing upwardly through the arm standard 3 and having, at its upper end, a strap 52 embracing an eccentric 53 adjustably secured to the belt-pulley H for rotation with the mainshaft 1. The adjustable eccentric 53 is of well known construction and corresponds substantially with the disclosure in the U. S. patent to W. F. Dial et al., No. 718,988, Jan. 27, 1903.

When the slide-block 38 is disposed at the stop-screw 41 side of the fulcrum-axis of the rock-lever 40, the eccentric 53 acts through the pitman 5|, rock-lever 40 and link 35 to oscillate the feed-advance rock-shaft 3| in timed relation with the rotating shaft |5 to effect vibratory movements of the rock-shaft crank-arm 33 which are unidirectional with the lateral movements of the feed-bar 22 derived from the eccentric |8. This will be understood by reference to the diagrammatic illustration in Fig. 6 of the drawings, wherein the solid lines represent the feed-bar 22 at the beginning of its rising and work-advancing movement and the crank-arm 30 in extreme retracted position, while the dotted lines represent the opposite limits of movement of said feedbar and crank arm. As the link 28, extending from the crank-arm 30, is connected with the feed-bar 22 between the eccentric l8 and the feed-dog 23, it will be apparent that the feed-dog will be maintained substantially horizontal during its work-advancing movement by reason of the fact that the point 21 of pivotal connection of the link 28 with the feedbar, 1. e., the floating fulcrum of the feed-bar, is advanced unidirectionally with the lower end of the feed-bar. Obviously, the amplitude of work-advancing movement of the feed-dog 23 may be controlled by adjustment of the eccentricity of the eccentric 53 and may be also treadle-controlled during the operation of the machine by shifting the slide-block 38 between the stop-screw 41 and the fulcrum-axis of the rocklever 40, to thereby vary the throw of the crankarm 30.

It has been common, heretofore, to provide a reverse feed mechanism in which a slide-block, operatively connected with a feed-advance rockshaft, is shiftable from one side to the other of the fulcrum-axis of an actuated rock-lever, to thereby relatively reverse the direction of movement imparted to the feed-advance rock-shaft. In the present case, the direction of feed is reversed by merely shifting the slide-block interponent 38 into a neutral position substantially coinciding with the fulcrum-axis 42 of the rocklever 40, this neutral position of the slide-block being determined by engagement ofthe slideblock with the stop-block 43 and rendering the feed-advance rock-shaft 3| stationary during the operation of the machine.

By referring to the diagrammatic illustration in Fig. 7 of the drawings, it will be observed that when the rock-shaft 3| is stationary, the link 28 has no endwise movement and the feed-bar 22 now swings about its floating fulcrum comprising the point of pivotal connection of said link with said feed-bar, whereby the direction of movement of the feed-dog is reversed in the raised position of said feed-dog.

Having thus set forth the nature of the invention, what I claim herein is:-

1. Feeding mechanism for sewing machines comprising, a feed-bar, a feed-dog carried by said feed-bar, a rotary actuating element in operative engagement with said feed-bar for imparting movements to said feed-dog in relatively transverse directions, a rock-shaft having a crank-arm, a controlling member pivotally connected to said crank-arm and providing a floating fulcrum for said feed-bar, and means for actuating said rock-shaft including an interponent manually shiftable during the operation of the machinefor rendering said rock-shaft inoperative.

2. Feeding mechanism for sewing machines comprising, a feed-bar, a feed-dog carried by said feed-bar, a rotary actuating element in operative engagement with said feed-bar for imparting movements to said feed-dog in relatively transverse directions, a controlling member pivotally connected to and providing a floating fulcrum for said feed-bar, means for actuating said controlling member in timed relation with said rotary actuating element to thereby supplement the movement imparted to said feed-bar in one direction by said rotary actuating element, and means manually operable during the operation of the machine for rendering the controllingmember actuating means ineffective.

3. Feeding mechanism for sewing machines comprising, a horizontally disposed rotary shaft, an actuating element carried by said shaft, a vertically disposed feed-bar embracing said actuating element, a feed-dog carried by said feedbar, a controlling member operatively connected to said feed-bar to provide a floating fulcrum for the feed-bar, means for actuating said controlling member to impart substantially horizontal movements to said floating fulcrum, and means manually operable during the operation of the machine for rendering the controlling-member actuating means ineffective.

4. Feeding mechanism for sewing machines comprising, a rotary actuating shaft, an actuating element carried by said shaft, a feed-bar embracing said actuating element and deriving movements therefrom in relatively transverse directions, a feed-dog carried by said feed-bar, a rock-shaft, a crank-arm carried by said rockshaft, a link having its opposite ends pivotally connected to said crank-arm and feed-bar and thereby providing a floating fulcrum for the feedbar, a rock-lever, means for actuating said rocklever, and connections for oscillating said rockshaft from said rock-lever including an element shiftable toward and from the fulcrum-axis of said rock-lever. 4

5. A reversible feeding mechanism for sewing machines comprising, a horizontally disposed rotary shaft, an eccentric carried by said shaft, a vertically disposed feed-bar embracing said eccentric and deriving relatively transverse movements therefrom, a feed-dog carried by said feedbar, a horizontally disposed rock-shaft, a crankarm carried by said rock-shaft, a link pivotally connected to said crank-arm and feed-bar providing a floating fulcrum for the feed-bar, a rocklever having a guideway substantially intersecting the fulcrum-axis of the rock-lever, means for actuating said rock-lever, a slide-block shiftably disposed upon said guideway and connected to said rock-shaft, spring means acting to yieldingly hold said slide-block in a position spaced from the fulcrum-axis of said guideway to efiect transmission of oscillatory movements to said rock-shaft and thereby work-advancing movements to said feed-dog in one direction, and means for shifting said slide-block into substantial alinement with the fulcrum-axis of said rocklever and thereby efiecting reversal of the direction of feed.

6. Reversible feeding mechanism for sewing machines comprising, a horizontally disposed rotary shaft, an eccentric carried by said shaft, a vertically disposed feed-bar embracing said eccentric, a feed-dog carried by said feed-bar, a

link having one end pivotally connected to said feed-bar between said eccentric and the workengaging face of said feed-dog, a crank-arm pivotally connected to the opposite end of said link, actuating mechanism for vibrating said crankarm in timed relation with said eccentric to impart work-feeding movements to said feed-dog which are unidirectional with the work-feeding movements derived by said feed-dog from said eccentric, and means controllable during the operation of the machine for rendering said actuating mechanism inefiective to vibrate said crank-arm and thereby effecting reversal of the direction of feed.

HENRY C. NISSEN.

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