US1177249A - Presser-foot mechanism. - Google Patents

Description

L. E. JOHNSON & E. ERICKSON. PRESSER FOOT MECHANISM. APPLlCATiON man APR.24. 1915.

1,137,249. Patented Mar. 28, 1916.

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LAWRENCE E. JOHNSON, OF WINTHROP, AND EDWARD ERICKSON, 0F LYNN, MASSA- CHUSETTS, ASSIGNORS TO VICTOR SHOE MACHINERY COMPANY, 013 BOSTON, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS.

PRESSER-IEOOT MECHANISM.

Application filed April 24, 1915.

To all whom it may concern:

Be it known that WB,LAWRENCE E. JOHN. SON, a citizen of the United States of America, and a resident of WVinthrop, in the county of Suffolk and State of Massachusetts, and EDWARD EmoKsoN, a subject ofthe King of Sweden, and a resident of Lynn, inthe county of Essex and State of *Massachusetts, have invented certain new and useful Improvements .in Presser-Foot Mechanisms, of which the following is a specification.

This invention relates to improvements in presser foot mechanisms for shoe sewing machines having for its object the produc tion of-adevice which will automatically accommodate itself to various thicknesses of material and in so doing will regulate the -length of thread to be drawn from the source? of supply. I

The present invention isanimprovement on U. S. LettersPatent No.'1,133,149, issued March; 23, 1915,and-to'which reference may be made for'the operation of certain parts of the machinewhich are not-herein shown, as they form no part of the inventionherein claimed.

The invention consists in certain novel features of construction and arrangement of parts'which will be fully understood by reference to the descriptionof'the drawings and to the claims herelnaftergiven.

Of the drawings: Figure 1 represents a vertical section of asewing machine, showrevoluble shaft 23is rotated by a driving wheel secured to one end thereof. Interposed between theside frames"21-;a'nd:keyed to the shaft 28 is the cam disk27 Tothe inner side of one of the side frames 21 is secured the work support28 which may be of any well-known construction.

i The thread 25 is drawn from any suitable Specification of Letterslatent.

Patented Mar. 28, 1916.

Serial No. 24,135.

source of supply and passes over afixed rod 103 extending from one side frame 21 to the other a pin 10% extending outwardly from this rod l03'positi0ning the thread If thereon and preventing it from slipping lengthwise thereof during the feeding of the work. The movement of the work in feeding is toward the left and the pin 10-1 is placed at the left of the thread to prevent slipping in that direction. The thread t then passes around a pin 105 secured to' the thread lock cam lever l06which is pivoted at 107 and has at its rear end a roller 108in the cam path 1.09 formed in the right hand side of the disk 27. V

The thread 27 passes from the pin 105 over a statlonary pin 110 in the side frame 21 and then through slots in two downwardly extending arms 111 of a forked member 112. The thread 6 passes from one arm 111 to the other arm 111 under a stud or pin-113 projecting horizontally from the side of the forward end of the lever 106. From the forked member 112 the thread t passes through a hole 114 in the movable frame 62 to an eye on one of the side frames 21 and thence into the wax pot 116 secured to the side frames 21in any well-known manner. To the front wall of the wax pot 116 is clamped, by means of the clamp screw 118, a support 119 provided with a sheavel2l around which the thread 2? passes through the liquid wax in said pot 116.

The disk 27 isprovided on itsright hand face with a cam path 1 11 in which is positioned a roller 14:2 mounted on the end of the lever 143 pivoted at 14A and provided at its outer end with a pivoted block 145 rack teeth 146in one edge thereof.

The pivot 14a is provided with a gear 117 on its inner end the teeth of which mesh with the rack teeth 14:6of themember 11.2. A plate 1&8 secured to the end. ofthe' lever 1 13 PIGVQIUJST the displacement of themembery112 This rack member 112 is provided with a lateral extension 149 to which is secured the, presser foot 150 of ordinary construction; The extension 1529 forms a head to the slidable member 112 which is adapted to contact with the upperface of the lever 143to limit the downward movement of said member 112.

Extending upwardly from the extension 149 and through the member 151 secured to the lever 143 is a rod 152 surrounded by a helical spring 153 which tends to retain the presser foo-t 150 in its normal position and against the tension of which said presser fort is adapted to be lifted.

The pivot member 144 is mounted in a tubular sleeve 154 revoluble in the frame 22 but prevented from end movement by the pin 155 extending into the annular peripheral groove 156 therein. The reduced end 157 of the sleeve 154 extends into the lever 143, this end 157 of the sleeve 154 and a porti n (If the shank 144 forming the pivot for said lever. The lower end of the presser foot 150 has an operating face 158 parallel with the upper face of the work support 28.

It is obvious that when the slidable member 112 is moved transversely of the outer end of the lever 143 the lower face 158 of the presser feet 150 and the upper face of the work support 28 will'remain constantly in parallelism in whatever position the presser font may be while exerting a gripping pressure upon the work.

Secured to the shank 144 is an arm 159 adapted to be manually operated to ad ust the presser foot 150 relative to the lever 143 and to acctmmodate it to varying thicknesses of material. This is accomplished by the operator moving the arm 159 and thereby turning the pinion 147, raising and lowering the presser foot at will.

- When any work is placed upon the support 28 the operator adjusts the presser foot in the manner just described so that it will rest upon the upper face of the work, after which it will be automatically adjusted as the material varies in thickness.

Opposite the end of the shank 144 and the outer face of the lever 159 secured thereto, is a friction member 160 consisting of a pad 161 in a recess in the inner face of the ear 162 on the lever 163, this pad 161 having a shank extending through and threaded to said ear 162 which shank is provided with a lccknut 164 to retain said pad in adjusted position.

The lever 163 is pivoted to the frame 22 and has at its rear end a roller 166 held in contact with a cam'in the right hand face of the disk 27 by means of a spring, as fully shown and described in said Patent 1,133,149, hereinbefore referred to.

lVhen the presser foot is moved downwardly by the cam controlled lever 143 the 5 work will be securely gripped thereby against the support 28, the face 158 being forced into the face of the work by the cam 141. The machines are built with a loose fit for therod 152 in the member 151 to permit of the member 112 being cramped between the guide wall 145 and the opposed face of the pivoted block 145 when the lever 143 is moved about its pivot 144. Just prior to the roll 142 entering the throw 160 to release the gripping pressure upon the worlr the pad 161 is moved into contact with the outer face of the lever 159 and locks the pinion 147, thereby preventing any sliding movement of the member 112. Consequently, when the roller 142 enters the throw 160 the presser foot 150 will be bodily lifted from the work and will remain free from contact therewith until the completion of the feeding operation, when it will be released and the spring 153 will be permitted to return the presser foot into light contact with the work before the roll 142 enters the concentric portion of the cam 141 to produce the gripping pressure upon the work.

Owing to the fact that the slidable member 112 is located outside of the pinion 147 and between it and the face of the block 145 pivoted to the lever 143, any movement imparted to said levcr 143 by the cam path 141 will be imparted to the presser foot 150, thereby removing it from the work when it is desired to feed the latter, or exerting a gripping pressure when the work has been fed. The main portion of the cam path 141 retains the operating face 158 of the presser foot 150 in contact with the work on the support 28 and causes it to exert a gripping pressure thereon, but when it is desired-to move the work along the support, the roller 142 of the lever 143 moves into the portion 160 of the cam path 141, thereby causing the presser foot tobe lifted from the work ternporarily'while said work is being moved upon the support into a new position.

The pin 113 is adapted to move in the forked end of the member 112, said pin being-moved by the action of the cam path 109 on the lever 106 in the end of which said pin is mounted. Thecam'path 109 is provided with a throw adapted to oscillate the lever 106 at the proper time to measure off the given quantity of thread for the stitch, the pin in doing this moving longitudinally of the slot in the end of the memher 112. As the thread t .in crossing this slot passes beneath the pin 113 it is obvious that if the slidable member 112 was always inthe same position a given length of thread would always be measured by the oscillation of the'lever 106 and the movement of the pin 113. It is desired, however, to measure off different lengths of thread for different thicknesses of material and this is readily accomplished by means of the slidable member 112, it being self-evident that when the presser foot 150 is raised the t ead carrving passages in the arms 111 of the member 112 are similarly raised to av new position corresponding with the thickness of the material and when in this raised position a greater quantity of thread will be drawn from the source of supply by the movement of the pin 113 in the forked end of the member 112, the lowermost position of said pin being the same under all conditions. It is obvious that this thread measuring device will operate after the presser foot 150 hasreturned into contact with the work. When the takeup device is operating, the pin 113 will be in its highest position and the pin 105 will be in position to coact with the pin 110 to lock the thread to prevent it from being fed from the source of supply.

The roller 108 is of less diameter than the width of the cam path 109 and is in contact with the inner wall of said path only when the lever 106 is being moved about its pivot to measure the thread. The roller 108 never contacts with the opposite wall of said path. The pivot member 107 has secured to its outer end an arm to the end of which is secured a spring the opposite end of which is fastened to the frame 21, all as shown and described in the patent referred to. This spring retains the pin 105 in contact with the pin 110 except during the thread measuring operation.

As described in the aforesaid patent, the pivot member 107 is revolubly mounted in an eccentric bushing in the frame 21 to which it is clamped by a bolt when adjusted by the handle. By adjusting the position of the pivot member 107 in this manner the normal length of thread for each stitch may be regulated, while by means of the mechanism for positioning the slide 112 the'supply of thread for various thicknesses of material may be automatically determined, the various lengths of thread measured off being proportionate to the thicknesses of material through which the thread is to be fed.

After the hook of the shuttle has carried the loop of thread to a point where it should be dropped to encircle and be drawn up with its companion thread to form a stitch, the takeup lever is operated to put the proper stress upon the needle thread to effect this result. It is then necessary to lock this thread betweenthe takeup and the thread supply (not shown) to prevent it from being drawn from the latter. This is accomplished by the locking pins 105 and 110, the cam path 109 being so constructed.

as to effect this result at the proper time. It will be seen that with this locking device 105110 the thread is positively held against movement without danger of the takeup stealing thread from the supply and failing to properly set the stitch.

The machine is pro ided with mechanisms for forming the stitch, feeding the work, forming the loop, all as fully described in Letters Patent of the United States No. 1.133,147 issued March 23, 1915, on which this application is an improvement." As these mechanisms form no part y by means of the screws 202 and a screw 203 extending therethrough and threaded to the outer end of the stud 200 as shown in Fig. 2.

The provision of thepivoted block 145 is of great importance for it has been found in practice that while a construction in which the slide 112 reciprocates between two parallel fixed walls works satisfactorily when new and when oil has not spread over its contacting surfaces, it does not work well when the parts have become worn or thoroughly lubricated and the cramping effect desired between the lever 143 and slide 112 will not be assured at all times.

It is quite essential that some provision be made so that the sliding member 112 will be positively locked to the lever 143 when the presser foot 150 is in gripping contact with the work and it has been found in practice that this result will be attained by the use of the pivoted block 145.

It is obvious that when, in the rotation of the cam disk 27 in the direction of the arrow a, the roller 142 moves from the cam throw 160 to the concentric portion of the cam path 141, the face 158 comes into contact with the work and tends to lift the presser foot 150 which in turn will tend to cant the in the lever 143 formed by the guide wall 145 and the opposed face of the block 145. When this canting of the slide 112 occurs the block 145 will be moved about its pivot 200 causing the upper end thereof to move inwardly toward the fixed guide wall 145 and thereby forcing the sliding member 112 into such firm contact therewith that any sliding movement of the member 112 is effectually prevented until this pressure is removed. This removal of the locking pressure on the sliding member 112 will not take place until the roll 142 again moves into the cam throw 160.

l/Vhen the block 145 becomes worn so as to be inoperative it may be replaced with a new block without discarding the entire lever 143 which was necessary when the guide walls 145 of the lever 143 were both formed integral therewith.

It is obvious that by the construction here in shown and described a very effectual presser foot mechanism is provided that is capable of regulating the amount of thread to be drawn from the source of supply, this amount depending upon the thickness of the material being operated upon.

It is believed that the operation of the mechanism and its many advantages will be.

trolled lever; a slidable member carried Copies of this patent may be obtained for five cents each, by addressing the thereby and movable transversely thereof at a point intermediate the pivot and outer end; a presser foot on said slidable member; a Work support; means for moving said slidable member endWise; a pivot pin in the outer end of said lever parallel to, its axis; and a block mounted thereon with a face thereof abutting the outer side face of said slidable member.

Signed by us at 4 Post Oflice Sq., Mass, this 22nd day of April, 1915.

LAlVRENCE E. JOHNSON. EDWARD ERICKSON.

Boston,

Commissioner of Patents,

Washington, D. C.

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