US2851975A - Feed control for shirring mechanism - Google Patents

Description

Sept 16, 1958 B. N. PIERCE FEED CONTROL FOR SHIRRING MECHANISM 3 Sheets-Sheet 1 Filed Deo. 16. 1954 Sept. 16, 1958 Filed Dec. 16. 1954 B. N. PIERCE FEED CONTROL FOR SHIRRING MECHANISM 3 Sheets-Sheet 2 [n ven or:

ernardNPI/'er-e @MQLM Sept. 16, 1958 B. N. PIERCE 2,851,975

FEED CONTROL FOR SHIRRING MECHANISM Filed Dec. 16. 1954 5 Sheets-Sheet 3 FEED CONTROL FOR SHIRRING MECHANISM Bernard N. Pierce, West Hartford, Conn., assignor to The Merrow Machine Company, Hartford, Conn., a corporation of Connecticut Application December 16, 1954, Serial No. 475,763

2 Claims. (Cl. 112-209) This invention relates to sewing machine feeding mechanism for Shirring or gathering material, and particularly concerns a control mechanism for varying the difference in the amount of feed effected by each feed dog to thereby determine the amount by which the material between the feeding devices is fulled.

In Shirring or gathering mechanism of the type to which this invention is applicable, a feed dog carrier is driven by a four motion mechanism to cause a feed dog mounted on the carrier to move in an orbital path. The relationship between the orbital path and the machine frame is determined by the location of a pivotal support on the carrier which constrains the motion of a portion of the carrier to a given path. In a typical mechanism of this type, front and rear feed dogs are moved in work feeding strokes of respectively different feeding effect so that certain material between the front and rear feed devices is fulled more or less according to the degree of differential effected by the strokes of the respective feeding devices. Such fulling of material may be applied to either one or more plies comprising the Work advanced by the feeding devices to suitable stitching elements.

An arrangement for controlling the amount or degree to which the ulling is effected is disclosed in co-pending application Serial No. 393,203, led November 9, 1953, by Bernard N. Pierce for Feed Control for Shirring Mechanism, now Patent No. 2,769,416. As disclosed in that application, the feed dogs are moved in orbital paths determined by positions of adjustable studs that pivotally support respective carriers of the feed dogs.

The object of the present invention is to provide an improved Shirring feed control mechanism with operating parts of the mechanism enclosed within the mechanism compartment of the machine frame or the feeding mechanism compartment at the end of the frame. Another object of the invention is to provide a link connection between a rock-shaft of feed control mechanism and a feed do-g carrier, so that the joints required in the arrangement are entirely pivotal in form and adapted j for compact installation where bulk would be diicult to accommodate. Another object is'to provide a shield in the mechanism compartment to prevent lubricant that is centrifugally discharged from rotating parts in the compartment from being expelled through a slot in a machine frame wall through which the free end of an actuating lever extends from the rock shaft of feed controlling mechanism.

In the attainment of these objects, one feature of the invention resides in the arrangement of a rock shaft with one endin the mechanism compartment of the machine frame, and the other end having a collar thereon from which an eccentrically disposed stud projects beyond the exterior of the mechanism compartment. The stud provides a pivotal support for one end of a link which at its other end is directly pivotally coupled by a pin to the rear end of the feed dog carrier to establish the Ifates Patent O position of the orbital path of the feed dog. From the end of the rock shaft within the mechanism compartment a lever is extended through a slot in the machine frame and serves to impart rotary movement to the rock shaft and thereby adjust the position of the pivotal link connections to change the position of the orbital path of the feed dog with respect to the work support or machine frame. Another feature of the invention resides in the provision in the mechanism compartment on one end of the rock shaft of a segmental stop cooperative with adjustable abutments for engaging the ends of the stop to limit angular displacement of the rock shaft. The end walls of the slot through which the rock shaft lever extends, limit the extreme range of rotation that may be imparted to the rock shaft. Another feature of the invention resides in an arrangement whereby a shield is interposed between moving parts within mechanism compartment and the slot through which the rock shaft actuating lever extends.

Other objects, advantages and features of the invention will become apparent from the following specification taken in conjunction with the accompanying drawings wherein:

Fig. 1 is an elevation of the left end of a Merrow overedge sewing machine with certain parts in section and others omitted or partly shown for purposes of clearness.

Fig. 2 is a sectional view on line 2-2 of Fig. 1.

Fig. 3 is a plan view showing machine frame and other parts in section.

Fig. 4 is a vertical transverse sectional View looking in a direction toward the left end of the machine.

Fig. 5 is a view looking toward the rear side of the machine with certain parts shown in section.

Fig. 6 is a sectional view on line 6-6 of Fig. 5; and

Fig. 7 is a sectional view through a mechanism compartment looking toward the rear side wall of the machine frame.

As illustrated in the drawings, this Merrow sewing machine is provided at its head or left end with a bearing 11 for a lower or main shaft 12 and with a bearing 13 for an auxiliary or upper shaft 14. For rotating shafts 12 and 14 in unison, means including cam cylinders 15 and 16, respectively fast on shafts 13 and 14, are provided with intermeshing gear tooth portions 17 and 18. These geared cylinder elements are provided with suitable cam grooves (not shown) as they form no part of the present invention. These cylinders 15 and 16 are housed Within a machine frame 19 enclosing a mechanism compartment 20 together with various other mechanism including certain parts of a feed controlling arrangement of parts about to be described.

Feeding mechanism of the machine and With which the present invention is concerned includes a front feed dog 21 secured to a carrier or feed bar 22. A rear feed dog and its carrier are not here shown but the relative action of a front and rear feed dog required to produce shirred work is extensively exemplified in the prior art. A detailed description of the feed mechanism may be. found in co-pending application Serial No. 301,426, filed July 29, 1952, by Edward R. Lamoureux and Bernard N. Pierce for Feed Control for Shirring Mechanism, now Patent No. 2,769,417. The pertinence of this disclosure will make it clearly understood that feed dog 21 is actuated in an orbital path determined primarily by movement of carrier or feed bar 22 imparted by eccentrics, on and rotating with the main shaft, and that the location of this orbital path With relation to a work support on the machine frame is adjustable to vary the feeding effect of feed dog 21. Endwise or to and fro movement of feed bar 22 is effected by an eccentric 23 on shaft 12. A link 24 engages this eccentric at one end and at its other end the link engages a stud 25 extended from feed bar 22. Up and down movement offeed' bar 22 is effected by eccentric 26 on-'shaft-:ll Thisi'eeentric'has sleeved'thereon fa blo'ek27'1slidableih?a`yke 2S`tliat is 'formed 'in feedbar 22. Pivotal :support of feed'baraZZ vadjacent-its rear'endlis providedby pin 29.

The -present invention `concerns an arrangement of parts 'for shifting Ipin l29 with respect to lfram'e 519 to therebych'ange the position ofthe orbital path in which feed dog `21 is moved so that the -orbit of the feeddo'g, as determined by the carrier on which-it is mounted, may be `located in different positions with respect to vthe machine frame to effect 'various results.

-A rock shaft() is rotatable in a'bearing bushing or sleeve 31, fsecured i'na bore '32 of machine frame 19, as -by 'a set screw33. The outer -end of bore 32 provides alrecess 34 to accommodate -a head-or collar 35 of rock shaft 30. From collar 35 an eccentrically located stud proj'ects into a channel 37 formed in a bracket 38 secured to machine frame 19 as by screws 39. Connecting rock shaft 30 to feed carrier or bar 22 is a link 40 extending beyond channel 37 from rock shaft stud 36 to pin 29 which directly and pivotally couples link 40 to feed bar 22. Thus movement of rock shaft 30 transmits motion to feed bar 22. Parts for manually actuating rock shaft 30 are -mounted on the end of said shaft that is -extended into mechanism compartment 20. Included in -these parts is a hub 41 secured to rock shaft 30 by a set screw as 42. Fixedly secured upon a reduced end of hub 41, as by brazing,is an actuating lever 43, vwhich extends to the exterior of machine Yframe 19 through a slot 44, the end walls 45 and 46 of which are inclined downwardly toward mechanism compartment 20 to resist lubricantflowingtherealong to the exterior of frame 19. Manually operable means of any suitable type maybe secured to the end of'lever 43 at the exterior ofthe mechanism compartment. A chain connected to an actuating treadle (chain and treadle are not shown) is one conventional arrangement for actuating the rock shaft 30.

To limit the angular displacement imparted to rock shaft 30, a stop element 47 is formed on the outer end of -hub 41 within mechanism compartment 20. This vstop element 47 is of segmental form having end surfaces 48 and 49 which are respectively engageable by abutments 50 and 5'1'on the ends of screws`52 and 53 'which extend through the rear wall of the machine. A desired adjustment of abutment '50 with respect to stop surface 48 :may be obtained by turning screw 52, and for securing such adjustment against accidental displacement, awasher 54 and suitable lock nut 55 are provided. Similarly, screw 53 is effective with respect to stop surface 49 and abutment 51 and is provided with a washer 56 and lock nut 57. From the foregoing description it will be apparent that the limiting stops presented by abutments 50 and 51 determine definite positions between which the orbital path of feed dog 21 may be adjusted relative to a cooperating work supporting surface.

A tension spring 58, which is connected between element 59 on the stop member 47 and element 60 on the machine frame 19, normally urges the rock shaft 30 in a clockwise direction as viewed in Fig. 6 so stop surface 48 engages abutment 50 on the screw 52. Actuating lever 43 may be moved to rotate the rock shaft 30 and thereby change the location of pin or stud 29 forming thecpivot for feed bar 22 to effect change in the position of the orbital path in which feed dog 21 is moved. The limit of movement of rock shaft 30 effected in opposition tothe tension of spring 58 is determined by the position of abutment 51 for engaging stop surface 49 on the *segmental stop 47. Usually, the two adjustable stops in the form of abutments 50 and 51 determine two positions of l-rockshaft 30 to provide two different `degrees of dif- Lferefntial -feed for feed dog l21ai1d a-rear feed dog (not 4 shown). Thus, through .manipulation of actuating lever 43, feed bar pin 29 may be established in either of two positions at the will of the operator, such positions having been predetermined to give the desired results by appropriate adjustment of stop screws 52 and 53. Obviously, the operator can also maintain ythe rock shaft at any Y position intermediate the limits, if desired, by manipulation of lever 43.

It is desirable that extreme range of angular displacement of'rock shaft 30 be so limited as to prevent pin or stud 36 on the rock shaft, from being moved to positions which are impractical. For this purpose the length of sl'ot `44 is maintained between end walls 45 and 46 which respectively serve as stops for limiting movement of lever 43 and thereby determine the extreme positions to which rock shaft 30 may be turned.

For suitable lubrication, of the bearing surfaces of moving parts within mechanism compartment '20, a'suffieient amount'of oil is conducted thereto and is thence impelled to distal points or'peripheries from which it is discharged, as by centrifugal force. For example, one plane wherein 'such discharge is vconsiderable is coincident with the termination of peripheral surface 63 of cylinder -I16 where the cylinder is stepped down to a lesser diameter-through bevel surfaces 64 and 65. In as much as the plane indicated is substantially that in vwhich lthe machine frame slot 44 extends, it is desirable that a shield be interposed between said Aslot 44 and any other zones from which oil is prone to be discharged, as from camcylinderllS,'otherwise oil would be expelled through the -slot Vand become detrimental. A suitable shield is ltherefore provided. It may comprise an angle bracket 66 having one leg 67 secured by screws as 68 to machine frame '19 vand 'a leg 69 to whichis secured an angle plate 70 as by rivets 71. ,'One leg 72 of angle plate 70 extends between cam cylinders 16 and 15 and the otherleg 73 Vextends v'downwardly a suitable distance to intercept oil discharged toward slot 44.

The lforegoing description discloses a preferred embodiment of my invention. The disclosed embodiment isc'apable of modifications which will be apparent to those skilled in theart and thereforethe above specification is intended tobe exemplary rather than limiting andthe true scope of my invention is that defined n'the'following claims.

I claim:

1. In a sewing -machine having a frame enclosing va mechanism compartment, a rock shaft within said mechanism compartment journaled in vone wall of said frame, a stud eccentrically mounted on one end of said rock shaft 'and projecting from `said shaft to the exterior of said frame, a link pivotally secured at one end to said stud, a pin'mounted at the other end of said link, a feed dog carrier pivotally supported directly upon said pin at the exterior ofsaid mechanism compartment, drive means 'extending from said mechanism compartment'for driving 'said carrier in'an orbital path, means secured to saidroc'k shaft for imparting rotary movement to said rock shaft to shift said link with its associated pin and therebyshift the position of said orbital path with respect to said vframe, a pair of adjustable abutments mounted in said frame and extending into said mechanism compartment to engage said rock shaft to define'respective limits of angular displacement of vvs'aid rock shaft, and resilient means normally biasing said rock shaft to one of said limits of angular displacement. y

2. In a sewing machine having a frame enclosing a mechanism compartment, a rock shaft journaled in 'one wall of said frame, a ystud Yeccentrically mounted on'o'n'e end of said 'rock shaft and projecting from said shaft to the exterior `of saidframe, a link 'pivotally secured at one enti to said stud, a `pin mounted 'at the other end of 'said link, a feed dog carrier pivotally supported directly upon said pin "at theexterior of'said mechanism 2,851,975 Y v 5 6 compartment, drive means located within said mechanism References Cited in the tile of this patent compartment and projecting from said compartment to Y drive said carrier in an orbital path, a lever xedly UNITED STATES PATENTS mounted upon said rock shaft Within said mechanism 1,002,265 Greb Sept 5, 1911 compartment and projecting through a slot in said frame 5 1,834,488 Zeiel OC'L 25, 1932 to the exterior of said mechanism compartment to impart 2,157,370 WCS May 9, 1939 rotary movement to said rock shaft to shift said link With 2,496,817 Schulthess Feb- 7, 1950 its associated pin and thereby shift the position of said 2,659,330 KHHUS NOV` 17, 1953 orbital path with respect to said frame, and a shield located within said mechanism compartment to intercept 10 FOREIGN PATENTS oil discharged from moving parts within said compart- 848.593 Germany Sept. 4, 1952 ment toward said slot.

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