US2889793A - Sewing machine - Google Patents

Description

June 9, 1959 c. w. MUELLER ETAL 2,889,793

SEWING MACHINE Filed July 25, 1952 9 Sheets-Sheet 1 r 1 INVENTOR- June 9, 1959 Filed July 25, 1952 c. w. MUELLER ETA L 'SEWING MACHINE 9 Sheets-Sheet 2 INVENTOR.

c. w. MUELLER EI'AL 2,889,793

SEWING MACHINE June 9, 1959 Filed July 25, 1952 9 Sheets-Sheet 3 FIG. 2A.

: fiGVENTOiI a BY fined 3% June 9, 1959 c w MUELLER ET 2,889,793

SEWING MACHINE Filed July 25, 1952 9 Sheets-Sheet 5 June 1959 c. w. MUELLER ETAL 2,889,793

SEWING MACHINE Filed July 25, 1952 9 Sheets-Sheet 6 FIG. 6A.

INVENTOR.

SEWING MACHINE Filed July 25, 1952 9 Sheets-Sheet 7 IN VEN TOR. M v M u BY M 7 June 1959 c. w. MUELLER ET'AL 2,889,793

SEWING MACHINE 9 Sheets-Sheet 8 Filed July 25, ,1952

INVENTO r Iii FIG.II.

June 9, 1959 c. w. MUELLER ETAL 2,889,793

SEWING MACHINE Filed July 25, 1952 9 She ets-Sheet 9 FIG. 13. FIG. |S.-

m m m 92 37 SEWING MACHINE Charles W. Mueller, St. Louis, and Thomas D. Taylor, University City, Mo., assignors, by mesne assignments, to Union Special Machine Company, Chicago, 111., a corporation of Illinois Application July 25, 1952, Serial No. 300,812

2 Claims. (Cl. 112-176) The invention herein disclosed relates to a blind-stitch sewing machine.

An object of the invention is to provide a machine of the kind mentioned that utilizes a rotary loop taker. Another object of the invention is to provide an arrangement for severing the thread at the end of a stitching cycle. A further object of the invention is to provide a machine in which the needle oscillates in a plane parallel to the longitudinal plane of the bed of the machine. An additional object is to provide a chain-stitch, blindstitch machine that utilizes a rotary looper with a shogging needle.

The foregoing objects and certain advantages that will hereinafter appear are realized in the embodiment of the invention illustrated in the accompanying drawings and described in detail below, from which description a clear understanding of the invention may be had.

The drawings include:

Fig. 1 and Fig. 1B which are side elevations, partly in section, of a machine embodying the invention;

Fig. 2A and Fig. 2B which are side elevations, partly in section, taken from the side opposite to the view shown in Fig. 1;

Fig. 3 which is an end elevation with the cover plate removed and part of the mechanism broken away;

Fig. 4 which is a partial end elevation similar to Fig. 3, with parts broken away;

Fig. 5 which is a top plan of the presser foot;

Fig. 6A and Fig. 6B which are partial sectional elevations;

Fig. 7 which is a section taken on the line 77 of Fig. 6A;

Fig. 8 which is a section taken on the line 8-8 of Fig. 6B and illustrating a cam;

Figure 9 which is a partial end elevation disclosing the relation of certain levers;

Fig. 10 which is a partial, sectional plan taken on the Figs. 13, 14, 15 and 16 which are respectively a top plan, a bottom plan and opposite elevations of the looper;

Fig. 17 which is a fragmentary sectional elevation taken on the line 17-17 of Fig. 3.

The particular machine illustrated is properly designated a tacker. It is especially adapted to effect a predetermined number of stitches at a given spot, i.e., without movement of the material acted upon. Thus, this machine is especially suitable, for example, for tacking a label to clothing by stitching the label at a plurality of spots with a plurality of stitches at each location. There are, however, several novel features that are suit able for the ordinary chain-stitch, blind-stitch, sewing machine.

The machine includes a base 1 that may be secured to a table or other support, and a frame on which all, of the operating mechanism is mounted. The frame in- 2,889,793 Patented June 9, 1959 cludes a section 2 that rests upon the base and is pivotally secured thereto, from which section 2, a horizontal arm 3 extends. An upright post or column 4 is secured to the section 2 and a horizontal arm 5 extends from the upper end of the post above and parallel to the arm 3. On the end of the arm 5, there is a needle head 6 which extends downwardly towards the arm 3.

A presser foot 7 is secured to the lower end of the needle head. Above the presser foot a curved needle 8 is secured in a needle bar 9 that is oscillated so that the needle cooperates with a rotary looper 10 for forming stitches. The needle bar and looper are actuated in timed relation by actuating mechanism driven from av main shaft 11 that extends through and is journaled inthe arm 5. For this purpose, a pulley 12 is driven by. a belt (not shown) from a motor (not shown) that may be mounted below the table on which the machine is positioned. The pulley 12 is connected to the shaft through a stop motion mechanism, designated generally by the numeral 13. As this stop motion mechanism forms no part of the invention, except insofar as will hereinafter be described, and is comparable to that shown in the patent to Nelson, No. 2,609,773 it Will not be described in detail.

The needlev bar 9 is pivotally and slidably mounted on a fixed shaft 14, fixed in a boss 15 formed on the needle head. Oscillation of the needle. bar is effected through a connecting rod 16 that is connected through several joints at one end to an arm 17 extending from the needle bar 9 and at the other end to a crank pin 18 mounted on a transverse shaft .19. Rotation of the shaft 19, is effected through a gear 20, secured onthe end of the main shaft 11, and meshing with a gear 21 fixed on the shaft 19. V

The needle bar 9 is also shifted laterally or shogged upon the formation of a stitch, that is, when in the position in which the needle is withdrawn from the material. In this way successive stitches are slightly spacedapart, alternate stitches overlying. For the purpose of. shogging the needle bar, there is provided a bell crank lever 22 that is pivotally secured to the needle head on a pivot screw 23. On one arm 22a of the crank lever- 22, there is a roller 24 that extends into a slot 25 formed on the hub of the needle bar 9. The other arm 22b has a bifrucated end section 220 that embraces a cam 26 mounted on the end of shaft '27. Rotation of the shaft 27 causes actuation of the lever 22 and the shogging of the needle bar 9.

. The shaft 27 is rotated through a gear 28 secured on the end thereof in mesh with a gear secured on a substantially vertical shaft 30, between the ends thereof. On the upper end of the shaft 30, a gear 31 is fixed thereto. The gear 31 meshes with the gear 21 mounted on the shaft '19. Thus, the shogging of the needle bar is effected in timed relation with the oscillation thereof.

The lower end of the shaft 30 has gear teeth 32 formed thereon which mesh with an idler gear 33 rotatably mounted on a stud 34. Gear 33 meshes with another'idler gear 35mounted on a stud 36 and in mesh with a gear 37 secured on a looper shaft 38. The looper shaft 38 is thus driven from the shaft 30. The looper 10, which is shaped as shown in Figs. 13 to 16, includes a hook- 'support 45 extends, anode-forrncriplunger"46 ex. tendsthroughthe work's'upport 45; node-former 47 thesleeve and the shoulder formed on the plunger at the reduced portion thereof. Another spring 55 acts between the end of the sleeve 52 and the work support 45. In the raised position of the work support, that is when supporting work against the presser foot 7, the node-former extends above the work support and presses a node of the work through the presser foot and into the path of the needle.

The node-former and work support or clamp are manually retracted away from the presser foot for inserting and removing work from the machine. This is effected through the bracket 51 that is connected through a link 56 and lever 57 to a shaft 58. The lever 57 has a slot 59 therethrough that receives a boss 60 on a bushing 61 that is secured to the shaft '58 by a set screw 62. The bushing 61 has formed integral therewith a hollow internally threaded extension 63. A screw 64 extends through a lateral arm 65 on the lever 57 and is threaded into the extension 63. On the end thereof of the screw 64 there is secured, for rotation therewith, a serrated finger piece 66. A coiled, compression spring 67 surrounds the extension 63 and bears against the bushing 61 at one end and against the lateral arm or extension 65 at the other end. A retaining spring 68 engages the serrated edge of the finger piece. A collar 69 is formed integral with the finger piece and has a spherical sector end which engages in a complementary recess in the lateral arm 65 of the lever 57. By turning the finger piece, the lever 57 is caused to move upwardly against the spring or downwardly by the action of the spring.

pressure thereon.

The shaft 58 extends through the arm 3 and the section 2 of the frame. Manual actuation of the shaft 58 is effected through a shaft 70 that is journaled in a bracket 71 in the section 2 of the frame and extends through the rear wall of the section 2. On the extended end of the shaft 70, there is secured a lever 72 to which a chain 73 is attached, the chain being connected to a foot treadle (not shown). 'An arm 74 is fixed on the shaft 70 and is connected by a link 75 to one arm 76a of a lever 76 fixed on the shaft 58. The other arm 76bacts as a stop against hub of lever 74. One end of a spring 77 is connected to the arm 74 intermediate the ends thereof, and the other end of the spring is secured to a pin 78 fixed in the wall of the post 4. The spring acts in a direction to rotate the shafts 70 and 58 so as to raise the work support and maintain it against the presser foot.

The machine is started manually and stopped through 7 the stop-motion mechanism 13. The manual operation is effected through a lever 79 fixed on a shaft 80 that extends through the rear wall of the post, which lever is connected by a chain 81 to a foot treadle (not shown). When the lever is depressed, the main shaft 11 is connected to the pulley 12 and so rotated and the stop motion mechanism is released. This relation is maintained through a predetermined number of stitch-forming operations by a cam and cam follower.

In the arrangement shown, three cams 82, 83 and 84 are provided so that during a sewing cycle different numbers of stitches may be formed, as for example, six, eight or twelve. The cams are arranged side by side and fixed on a shaft 85 extending through and journaled in the walls of the post 4. The shaft 85 is driven from the main shaft 11 through reduction gears that include a worm 86 fixed on the main shaft; a worm gear 87 fixed on a transverse shaft 88; a gear 89 also fixed on the shaft 88; and a gear 90 fixed on the shaft 85. Thus, the shaft 85 is driven at a considerably reduced speed relative to the main shaft, in the machine illustrated in a ratio of twenty-four to one. The cams or control elements 82, 83 and 84 have spaced depressions such as indicated at 91 on the cam 84, each control element having a different number of depressions in accordance with the number of stitches to be made before actuation of of the stop-motion mechanism. In the arrangement illustrated, a maximum of twelve stitches are produced at any given stitching cycle. To this end, the cam 82 has four depressions in the surface thereof; the cam 83 has three, and the cam 84 has two. Thus, on a half revolution of the shaft 85, twelve stitches are formed. These cams or control elements, are of the same diameter.

Arranged to cooperate with one or the other of the control elements 82, 83 and 84 there is a cam follower 92 mounted on an arm 93 extending from one side of a yoke 94. The yoke 94 is free on the shaft 89, i.e. it may be moved angularly and longitudinally of the shaft. A boss 95 extends from the center of the yoke and through an elongated slot 96 in the side wall of the post. Within, and extending through the boss, there is a rod 97. A spring 98 surrounds the rod and at one end engages a collar 99 threaded in the end of the boss, and at the other end engages a transverse pin 100 extending through the rod. On the outer end of the rod, there is a knurled knob 101 by which the rod may be pulled outwardly against the action of the spring 98. The inner end of the rod 97 cooperates with a bracket 102 fixed on the shaft 80, the bracket having three rod-receiving openings 103, 104 and 105 in the face thereof. By pulling the rod outwardly, tilting the yoke and moving the yoke along the shaft, the rod may be brought to a position to enter any one of the three openings. When the rod 97 is in the opening 103, the cam follower 92 is in position to cooperate with the control element 82; when the rod is in the opening 104, the cam follower cooperates with the cam 83; and when in the opening 105, the cam follower cooperates with the control element 84. Through the rod 97 and the bracket 102, the yoke is connected to the shaft 33.

When the operator depresses the lever '79, the shaft 80 is moved about its axis and moves the cam follower out of the depression in the cam such as the depression 91 in the cam 84, it is then engaging and the machine is started so that when the operator releases the lever 79, the cam follower engages or rides on the cam surface and the shaft 80 is maintained in the position to which it was moved against the action of a spring 106. The machine continues to operate until the cam follower enters a depression in the cam. When this occurs the spring 106 rotates the shaft back to its original position and the stop-motion mechanism operates to stop the machine.

The machine is provided with thread-handling mechanism part of which is actuated during the stitch-forming operations and part of which is actuated upon operation of the stop-motion mechanism. In addition, there are the usual thread guides such as the post 107 and the guide 108 on the needle head cover. A thread take-up 109 is provided for taking up the thread as it is cast from the looper. The take-up is pivoted on a pivot screw 110 and is provided with a slot 111 having cam-engaging surfaces 112 and 113 which embrace an eccentric 114 on the shaft 19. An arm 115 on the take-up extends through the needle head cover and has an opening 116 therethrough for the thread.

From the thread guide post 107, the thread passes through the guide 108 and then between the discs of a thread nipper 117 that is periodically released for giving up thread through a lever 118. The lever 118 is pivoted at 119 and has an extension 120 that in the down position of the lever separates the discs of the nipper to release the thread. A spring 121 biases the lever away from the nipper, and a roller 122fixed on the crank 18 engages the edge of the lever to depress the lever and release the nipper. From the nipper 117, the thread passes between the discs of a thread tension 123, over an upturned hook-shaped, stationary guide 124, below a down-turned hook-shaped guide 125 mounted on a movable lever 126, and through a stationary eyelet guide 127. The thread then passes through the take-up 109, a snubber 128 mounted on the needle head cover, through a clamp 129 on the needle bar and thence through the eye of the needle. The guides 124, 125 and 127 cooperate to draw off a certain amount of thread at the end of a sewing cycle. This is effected through the lever 126.

The lever 126 is loosely mounted upon a shaft 130 so that it may move angularly relatively to shaft. Adjacent to and behind the lever 126, there is fixed to the shaft an arm 131. A pin 132 fixed to the lever 126 and extending laterally therefrom is positioned to be engaged by the upper edge of the arm 131 so that when the arm 131 is elevated, the lever 126 is also elevated. The lever 126 is biased towards the lower position thereof by a spring 133 which is secured at one end to a pin 134 fixed to the lever 126 and at the other end to a fixed bracket 135. In the elevated position, the end of the lever 126 engages a resiliently mounted plunger 136 which holds the lever in the elevated position during a stitching cycle. At the end of a stitching cycle, and upon the operation of the stop-motion mechanism, the arm 131 engages the resiliently mounted plunger 136, depresses the plunger and releases the lever 126. When the lever 126 is released and moves downwardly under the action of the spring 133 the hook-shaped guide 125 draws 01f thread for the start of the next stitching cycle. The amount of thread drawn off upon the downward movement of the lever 126 may be adjusted by an adjustable stop 137. This stop is threaded through the fixed bracket on which the guides 124 and 127 are mounted. The end of the stop is in position to engage the lower end of the lever 126. A knurled finger piece 138 is provided for adjusting the stop, which knurled finger piece engages a re silient detent 139 in the form of leaf-spring having a longitudinal detent 140.

The lever 131 is actuated upon the last five degrees of the rotation of the main shaft following the operation of the stop-motion mechanism. At this time the thread nipper 117 is open and the thread released. The operation above described provides a delayed action of the thread pull ofi lever 126. So that the pull off is effective, the nipper closes at the precise moment when the machine is actually stopped. The purpose of the action of the thread pull off is to provide thread for the first stitch of the next succeeding operation. Without such an arrangement the thread would be withdrawn from the needle. When the looper casts the thread the takeup is actuated to set the stitch. The nipper during this operation has the thread clamped. Just immediately 6 before the stitch is set the nipper is opened to release the thread.

The shaft 130, and in consequence the lever 131, is actuated in accordance with the movement of the shaft 80. For this purpose, a bracket 141 is fixed on the end of the shaft 80, and a bracket 142 is fixed on the end of the shaft 130. A link 143 connects the two brackets. Thus, when the shaft is actuated by the foot treadle the shaft is actuated to elevate the lever 131 and in consequence the lever 126. During the stitching cycle, the lever 126 is, as previously described, held in the elevated position by engagement with the resiliently mounted plunger 136. The shaft 80 is released by the cam-follower 92 entering a groove in one of the earns 82, 83 or 84, and the lever 131 moves the plunger 136 to release the lever 126. The arrangement of the brackets 141 and 142 and the link 143 is to provide greater movement of the shaft 130 than the shaft 80. The arrangement is in the nature of a compound crank operating to produce a ratio in the angular movement of the shafts.

Upon the completion of a stitching cycle, the operator actuates the shaft 70 through the lever 72 for the purpose of depressing the work support so that the work may be either removed or shifted. When the work support is depressed, the thread is moved across a knife for the purpose of severing the thread, and when the work support is released, a thread wiper moves the thread extending from the needle out of the way for insertion of another piece of work. These operations are effected through concentric shafts 144 and 145 which extend between the post 4 and the needle head. The shaft 144 is hollow and the shaft 145 extends therethrough and is rotatable therein.

For the purpose of severing the thread at the end of a stitching cycle, a stationary knife blade 146 is secured to the presser foot 7. The knife 146 is secured in a groove 147 in the presser foot. The knife is secured to the presser foot by a machine screw 148 extending through a slot 149 in the knife. With this arrangement, the knife may be adjusted. A cutting edge 150 is provided on the knife blade 146. The cutting edge of the knife blade extends across the path of the needle and part way across the node receiving opening 151 through the presser foot. In operation, the needle passes under the cutting edge or cutting extension of the knife. This knife blade is constructed of such material and is of a thickness that it is resilient or yieldable. At the end of a stitching cycle, the thread is drawn across the cutting edge of the knife blade.

The thread is drawn across the cutting edge of the knife blade by a finger 152 that extends from a plate 153. The plate is secured to the presser foot by two machine screws 154 and 155. One of the machine screws, 154 extends through an inclined slot 156 and the other machine screw, extends through a substantially L-shaped slot 157. An extension 158 of the plate 153 is provided with an angular slot 159 into which a pin 160 extends. The pin 160 is secured to one end of a lever 161 that is pivoted between its ends to the frame by a pivot screw 162. When the lever 161 is actuated, in a manner hereinafter described, the finger, as seen in Fig. 5, first moves upwardly and then to the right. The first part of the motion just described is to cause the finger to enter the triangular area formed by the thread as it emerges from the node and passes over the looper. The second part of the motion of the finger 152 is to cause the thread to move over the stationary knife blade which severs the thread close to the material. With this arrangement, the thread is cut close to the cloth and the end of the thread is not frayed.

The lever 161 is actuated by the shaft 144. To this end, an arm 163 is secured to the shaft 144 and is connected to the lever through a ball and socket fixture 164. Within the post 4, the shaft 70 is connected to a link 165. This connection includes a bracket 166 having an arm 167,

which bracket is secured on the shaft 70. To the end of the arm 167 the lower end of the link 165 is pivotally secured by a pivot screw 168. The link 165 extends up through the post 4 and has an end portion 169 that embraces the shaft 11. At the upper end of the link 165, there is secured thereto a cam-follower 170. This camfollower cooperates with a cam 171 secured on the shaft 11.

Intermediate the end of the link 165 there is secured thereto a cam-block 172 having a triangular cam projection 173 thereon. The cam projection is positioned to engage a cam-follower 174 secured to a bracket 175 that is fixed to the shaft 144. Thus, when the shaft 70 is actuated by the operator, the link 165 is moved downwardly, the cam projection 173 engages the cam-follower 156 and moves the shaft 144 as the cam moves past the cam-follower. Upon movement of the shaft 144, the plate 153 is actuated to cause the thread to be engaged by the finger 152 and drawn across the cutting edge of the knife blade 149, as the cam 175 moves past the cam-follower 174, the shaft is actuated and released by the cam. Upon release the plate 153 is returned to inoperative position by a torsion spring 176 wound about the shaft 144 and connected at one end to the shaft and at the other end to the The thread wiper 177 is also actuated in accordance with the movement of the shaft 70. To effect such movement, a bracket 173 is secured on the end of the shaft 145. To a radially extending arm of the bracket 178, there is secured one end of a link 179 by the pivot screw 180, the pivot screw extending through a slot 181 at the end of the link. The other end of the link 179 is secured to the link 165 by a pivot screw 182.

At the needle head, the thread wiper 177 is secured to the shaft 145 for movement therewith. This thread wiper consists of an arm 183 having a hook-shaped end 184 which extends into an opening 185 in the presser foot. The slot 181 in the link 179 is for the purpose of permitting a certain amount of movement of the link 179 be fore the thread wiper is actuated. In this manner, the thread is cut before the thread wiper passes across the path of the needle. A spring 186 biases the wiper to its ineffective position.

The link 165 having the cam-follower 170 thereon positioned to cooperate with the cam 171 serves several purposes. The cam 171 has a radial slot 186 therein into which the cam-follower 170 is received in the stopped position of the machine. In order to start the machine, the cam-follower 170 must be raised out of the slot. This is elfected by the spring 77 when the operator releases the lever 72. If the shaft 70 is not actuated to elevate the work support to the proper position, the cam-follower 170 will remain in the slot 186 and prevent the operation of the machine. This may be due, for example, to the failure of the spring 77 or due to the fact that too great a thickness of cloth is between the presser foot and the work support. However, if merely a slight additional thickness of cloth, slightly thicker than that for which machine is set, is placed between the work support and the presser foot the curved edge 187 at the outer end of the slot will engage the earn-follower 170 and elevate the link 165, and in consequence, the work support, to take care of the slight addition thicknesses.

From the foregoing description of the embodiment of the invention illustrated in the drawing, it will be seen that by this invention there is provided a blind-stitch, chain-stitch, sewing machine that operates through a stitch cycle, the number of stitches being variable at the will of the operator; a machine which at the end of the stitch cycle and upon the depression of the work support severs the thread and wipes the thread so that the machine is ready for the insertion of more work; a chain-stitch, blind-stitch machine that utilizes a rotary looper and a shogging needle; a chain-stitch, blind-stitch machine which at the end of a sewing cycle automatically draws 01f thread for the next sewing cycle so that the thread is not withdrawn from the needle; and a machine that is ideally suited for what is known as tacking operations.

It will be obvious, that various changes may be made in the details of the embodiment of the invention disclosed in the drawing by those skilled in the art within the principle and scope of the invention as expressed in the appended claims.

We claim:

1. In a blind-stitch, chain-stitch sewing machine, the combination comprising a work support, a pivotally mounted needle-bar, a curved needle carried by the needlebar above the work support, a rotary looper mounted for rotation about an axis substantially perpendicular to the work support and positioned above the work support for cooperation with the needle, said rotary looper having a needle opening intermediate the ends thereof, a hookshaped section on one side of the needle opening for taking a loop of thread formed on the retraction of the needle, and a section on the opposite side of the needle opening for turning and positioning the thread loop for penetration on the subsequent stroke of the needle, means for rotating the looper in timed relation with the oscillation of the needle-bar, a thread take-up, and means for actuating the thread take-up in accordance with the oscillations of the needle-bar.

2. In a blind-stitch, chain-stitch sewing machine, the combination comprising a frame including a base, a column extending vertically from the base, an arm extending laterally from the column and a head extending downwardly from the end of said laterally extending arm, a work support below the lower end of said head, a presser foot carried by the head and positioned above the work support, a needle-bar carried by the head, positioned above the presser foot and pivotally mounted for oscillation in the plane of said laterally extending arm, means for oscillating the needle-bar, a rotary looper carried by said head and positioned above the presser foot, said rotary looper being positioned to rotate in a plane parallel to the base and having a needle opening intermediate the ends thereof, a hook-shaped section on one side of the needle opening for taking a loop of thread, and a section on the other side of the needle opening for turning and positioning a thread loop taken by said hook-shaped section, means for rotating the looper in timed relation with the oscillation of the needle-bar, a thread take-up, and means for actuating the thread take-up in accordance with the oscillations of the needle bar.

References Cited in the file of this patent UNITED STATES PATENTS 420,449 Hall Feb. 4, 1890 472,512 Russell Apr. 5, 1892 752,451 Henderson Feb. 16, 1904 814,642 Dearborn Mar. 6, 1906 826,094 Fefel July 17, 1906 1,172,812 Lewis Feb. 22, 1916 1,514,713 Mueller Nov. 11, 1924 1,734,822 Mueller Nov. 5, 1929 1,785,412 Hatfield Dec. 16, 1930 1,802,212 Lutz Apr. 21, 1931 2,188,228 Mueller Jan. 23, 1940 2,374,043 Simmons et al. Apr. 17, 1945 2,618,232 Mikolas Nov. 18, 1952

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