US1940501A - Sewing machine - Google Patents

Description

M. MCCANN SEWING MACHINE Dec. 19, 1933.

Filed April 9, 1930` 3 Sheets-Shea?l l :Zigi y A TTORNEY Dec. 19, 1933. M. MccANN 1,940,501

SEWING M ACHINE Filed April 9, 1930 3 Sheets-Sheet 2 Egg/WM A TTORNEY Dec.'19, 1933. M. MCCANN SEWING MACHINE Filed April 9, 1930 3 Sheets-Sheet 3 l g al ATTORNEY Y Patented Dec. 19,1933

4UNITED t STATES 1,949,591 sEWm'G MACHINE Michael McCann, St. Albans, N. Y., assignor to Frederick Osann Company, New York, N. Y., a corporation of New York Application April 9,1939. serial No. 442,723

9 Claims.

chine incorporating a special form of binding tape folding mechanism in an improved arrangement in the machine relative to my improved 'trimming mechanism and the stitching mechanism, all of which are arranged to Ajointly provide a piece of material with a uniformly bound edge portion. A further object is the provision of a sewing machine trimming mechanism wlthan improved construction and arrangement of the trimming knife operating connections and an lmproved construction of the mechanism'for throwing the trimming knife into and out of operation. A further object is the provision of a sewing machine trimming mechanism with improved means for guiding the movements of the trimming knife during its operation. A furtherA object is the provision of a sewing machine presser foot with means cooperating with portions of the trimming 3 mechanism in effectively disposing of the material removed by the trimming knife. A further object is the provision of a sewing machine of the above described character which is simple, compact, positive in operation, and which efliciently attains the objects above set forth.

The various features of novelty which characterize my invention are further pointed out in the claims annexed to and forming 4a part of this specification. For a better understanding of the invention, however, and the advantages possessed by it, reference should be had to the accompanying drawings and descriptive matter in which I have illustrated and described a preferred embodiment of the invention.

Of the drawingsz- Fig. 1 is an elevation of the outer end of the machine with the head plate removed to more clearly show certain portions of the operating mechanism, and with the needle bar .and trimming knife in their uppermost operative position;

Fig. 2 is a front elevation of the head with the front side of the head casing broken away to show a front view of the mechanism illustrated in Fig. 1, with the trimming mechanism in its inoperative position; p

Fig. 3 is a front elevation oi' a portion of the mechanism shown in Fig. 2, with the trimming mechanism in its uppermost operative position; co

Fig. 4 is a view similar to Fig. 1, illustrating the trimming mechanism in detail;

Fig. 5 is a horizontal section on the line 5-5 of Fig. 2;

Fig. 6 is a horizontal section on the line 6-6 05 of Fig. 3;

Fig. 7 is an enlarged front elevation partly in section of the trimming knife guide block arrangement; and

Fig. 8 is a horizontal section on the line 8 8 10 of Fig. 2 with the presser foot omitted for purposes off-clarity. v

While the, present improvements are adapted to be incorporated and used in various well known typesof lock stitch and chain stitch sewing machines, they are especially adapted for use in sewing machines of the rotary hook type and are hereinafter described in connection with a machineof this type. Many oi' the parts o1' the machine illustrated are or may be similar, or substantially similar, to those of this type of sewing machine as heretofore constructed, and for these parts, other parts, diierent in form but similar in function, may be readily substituted. Among such parts are an overhanging hollow arm A, a vertically elongated hollow head A integrally formed at the outer end of the arm A and having yits open outer end closed in the usual manner by a head plate (not shown), a bed plate A2, a needle plate A3 containing the usual needle opening A", a needle bar A4 carrying an eye-pointed needle A5, and a presser bar A". vThe presser bar AI and needle bar A4 are arranged for vertical reciprocation in sleeve bearings A8 located in and extending through corresponding openings in the lower end of the head. A main upper drive'shaft B extends axially in the arm A with its outer end portion journalledin a partition A9 separating the interiors of the arm and head. The outer end oi.' the shaft B carries an eccentric B', as shown, from which a crank pin B2 projects outwardly. A pitman B3, extending downwardly adjacent the louter face of the eccentric B', is pivotally connected to the pin B2 and to a lateral arm B4 of a clamp B5, which is secured to the upper end of the needle bar, and by which parts the usual needle and needle bar reciprocating movements are eifected and controlled. A well known form of hand lever B6 for raising and lowering the presser bar AI in opposition or conjunction, reu spectively, with a coiled spring B" is also illustrated. A take-up rod C is also driven from the main shaft B. The take-up drive includes a crank C and a crank pin C2, the latter being pivotally connected to a sleeve C3, which is slideably mounted on the take-up rod C, and all lof, whichcollectvely effect oscillatory movements of the rod. Ihe take-up frod is formed with a lateral end section C4 having the usual thread opening C5 and f with those of the needle bar.

extending through a curved slot in the head plate.

As stated heretofore, the improvements are preferably incorporated in a rotary hook sewing machine, because of the high speeds possible in this type and its Vcapacity for incorporating the improvements evolved without materially reducing the speed of operation. The machine includes a rotary hook shaft D, preferably driven from the main drive shaft B through suitable driving connections mounted in the machine standard. A rotary hook Ds is carried at the head end of the shaft D and constructed to receive a bobbin and bobbin case in the usual manner. The bobbin case is removably held in its operative position by a cup-shaped disc D', swingable outwardly on pivots D2 to permit the insertion and removal of the bobbln structure. A latch D3 holds the disc in its normal operating position. A cloth feed D4 extends through openings in the needle plate and is actuated through eccentrics from shafts D5, at each side of and operatively connected to the shaft B.

The trimming mechanism, as preferably constructed in accordance with the present invention, comprises a vertically reciprocable trimming knife E in the form of a flat faced vertically elongated blade having a lower cutting edge E' formed, as shown best in Figs. 1, 4 and 7, with successive inclined portions E2 and E3 extending forwardly from a substantially pointed rear end. The knife is preferably positioned a substantial distance forwardly and slightly inwardly of the needle A5.

The knife E is provided with a vertical slot E4 in its upper end, which is vertically slideable in, and held against forward or rearward movements by, side flanges E5 formed on a knife block E6. A screw E7, extending'through the slot E4 and engaging the block E, holds the knife in any desired vertical position. As shown in Figs. l, 2 and 4, the knife block E6 is formed at its inner side with a. horizontal tongue E8 extending substantially throughout its entire length and slidably fitting in the groove formed by a pair of vertically spaced horizontal flanges F on the forward end of a. knife carrier F. The desired horizontal position of the block E in the groove is maintained by a screw F2 extending through a horizontal slot F3 in the carrier into engagement with the block. By the foregoing provisions, the vertical and horizontal positions of the trimming knife in the vertical plane of its body relative to the carrier F and adjacent machine parts can be readily adjusted for varying operating conditions.

Substantially similar adjusting means are provided for the connection between the knife carrier F and a vertically reciprocable knife bar H. As shown in Figs. 3, 4 and 6, the carrier F has a vertically and laterally extending body portion F4 provided with a horizontal tongue F5 slideably fitting into the groove formed by a pair of vertically spaced horizontal flanges H' on the knife bar mechanism and held in any desired posi* ion by a screw F and slot F1, as described heretofore. The flangesv H' are formed at the front side of a clamping member H2, the legs H3 of which surround and are secured to the lower end 0f the knife bar H by a bolt H4. The knife carrier and thereby the knife are thus arranged for horizontal and vertical adjustments relative to the knife bar. An operating vfinger F8 projects inwardly from the carrier.

, The parts of the trimming mechanismhereto- V'fore described are arranged to be operatively connectedto the drive shaft B for vertical reciprocating movements similar to and synchronized The trimming mechanism drive connections include an eccentric G on the shaft B between the partition A9 and the inner side of the needle bar eccentric B. A strap l(Ei2 encircles the eccentric and carries a vdepending arm-(33, which is'pivotally connected to a horizontal pin G4. The pin G4 is rigidly mounted ,inja clamp member G5, which is arranged to be operatively connected or disconnected from the knife bar H by a throw-in-and-out mechanism. The inner side of the head is .cut away as shown in Fig. 2 to permit the driving parts to be positioned 'therein and to move vas is hereinafter described. g

The throw-in-and-out mechanism, as shown in Figs. 2 to 5, consists of a Ahorizontal tubular casing J of relatively small diameter and from the outer end' of which the clamp G5 projects vertically. A plunger J is axially movablev in the casing J towards its operative or engaging position by the action of a coiled compression spring J2 surrounding the plunger stem and to an inoperative or disconnected position by the manual operation of an angular finger J3, which is detachably connected to the inner end of the plunger; The horizontal section of the finger J3 contacts with the attened inner end of the casing J. The knife bar H carries a block K, of the general form shown in Fig. 5 and incorporating clamping parts K3 by which it is secured to the upper end of the bar. The block K has a forwardly extending section K terminating in a vertical inner face K8 at the outer side of and adjacent to the outer end of the casing J. A horizontal recess K2 is formed across the face K8 and into which the slabbed outer end J9 of the plunger J is arranged to automatically move when the parts are in horizontal alignment to operatively connect the drive'shaft B and knife bar H. When the plunger J is withdrawnfrom the recess Kz by operating the finger J 3, it is evident that the knife lbar and drive shaft will be disconnected and no trolled by a rocker arm J4 integrally connected to and extending rearwardly from the plunger casing J. The rear end of the arm J4 is formed with a hub J5, which is rotatably mounted on a horizontal pin Ja clamped in a. bracket Jrl on the rear side of the head A'. By the foregoing provisions, the plunger J is maintained during its disconnected vertical movements in contact with the face K8.

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With the described construction and arrangement, the plunger would necessarily return to its l-QO lower end of the head and extending vertically through an opening K5 in the block K. A spring K6 is coiled about the'post K4 between the lower face of the block K and the head. The spring K6 is under compression at all times when the knife bar is being operated and, when the plunger J is withdrawn, automatically raises the recess K2 above the range of movement of the plunger on the face K3;

The knife bar may be returned to a lower engaging position by the operator depressing the finger F2, at which position the plunger will automatically enter the recess K2 and again connect the knife bar to the shaft B. To insureengagement of the plunger and block during this movement, the portion of the block determining the upper face of the recess K2 is extended to form an inwardly projecting shoulder K", which as shown in Fig. l, prevents the movement of the block K downwardly by the operator past the plunger engaging position. 'I'he limiting action is effected by the shoulder abutting the upper surface of the outer end of the plunger. The plunger will thus snap into the recess and operatively connect the knife bar and drive shaft whenever the finger F8 is depressed.

As shown particularly in Figs. 2, 3, 6, and 8, the trimming mechanism also includes a stationary knife M, horizontally arranged in a recess M' in the upper surface of the needle plate A3 at a point in front of the needle and is provided with a rearwardly extending cutting edge M2 which cooperates with the knife E. The knife M is held against movement by the edges of the recess M' and by a screw M3 engaging the needle plate. The portion of the needle plate and bed plate inwardly of the cutting edge of the knife M is cut away, as shown in Figs. 2, 6, and 8, to permit the insertion therein of a guard member N for disposing of the cuttings removed from the material by the trimming knives.

The guard N is constructed with a horizontal lip N resting on the bed plate inwardly and in front of the knife M, a depending substantial rectangular cutting receiving section N2 below the cutting edge of the fixed knife M and having an outer vertical wall N3 contacting with the lower face of the blade M adjacent its cutting edge, a vertical rear wall N4 extending upwardly adjacent the rear edge of the knife E, and a horizontal bottom plate N5 terminating in an inclined apron section N6. The rear wall N4 extends upwardly above the surface of the bed plate with its outer corner portion terminating in a forwardly extending cutting defiecting section N", the lower edge N8 of which extends substantially horizontally alongside of the inner face of the blade E. The guard N is held in position on the bed plate by screws Nlo passing through short horizontal slots N11, which permits a limited lateral adjustment of the guard.

Associated with the guard member and other parts described is a presser foot O adjustablyand detachably mounted on the lower end of the pressed bar Al and adapted to be raised and lowered therewith by the lever B6. The presser foot proper is of a well known form, with the addition of a guard O' having a lateral arm O2 mounted on the upper side of the inclined end of the presser foot and horizontally adjustable thereon by a horizontal slot O3 and screw O4'. 'I'he guard O' extends alongside the inner edge of the foot in front of and substantially in vertical alignment with the knife E, and with its inclined lower edge O5 slightly spaced from the upper surface of the knife M when the presser foot is in its lower or operating position. The guard O' is formed with a laterally off-set section O6 extending rearwardly between the inner face of the knife E and the edge N8 of the guard N and substantially closing the space at the inner side of the trimming knives, and whereby the cuttings or clippings removed by theknives are prevented from passing rearwardly over the fixed knife and being subsequently sewed on the material. Normally, the clippings drop into the guard section N2 and slide down the apron N to deposit in a suitable receptacle cron the floor below the machine.

It is particularly important that the cutting vedges of the trimming knives be maintained in a fixed relative position irrespective of the character or quantityof the material operated on. The trimming knife M is fixed in the recess M' and a guide block P is provided for preventing any inward deection of the knife E. As shown in Figs. 3, 4, 6, and '7, the guide block P is in the form of a channel having vertically spaced horizontal flanges P arranged to slidably t on a short horizontal bar P2, which is secured to the rear wall N4 of the guard N in any suitable manner adjacent to the inner4 face of the knife E. 'I'he guide block has a short horizontal slot P3 through which a screw P4 extends into engagement with the bar P2, providing a limited horizontal adjust- 'ment of the block. The outer end of the block may be thus positioned to contact with the inner face of the knife E during its reciprocatory movements and insure a close contact between the movable and fixed knives in operation. y

A binding tape folding deviceR is advantageously associated with the trimming and stitching mechanism heretofore described. The tape folding device utilized is of a well known form and is arranged in a surface recess R in the needle plate with its outer end extending into an arcuate recess O", formed in the inner side of the presser foot immediately before a needle opening O8 in the latter. A binding tape of the proper width is inserted in the inner expanded end of the device and withdrawn through an arcuate opening R2 having reversedly curved end portions R3 in the outer contracted endwhereby the tape is folded along its longitudinal center line and its edge portions folded outwardly. As the tape passes out of the folder, it is turned rearwardly through a semi-circular recess l.3 which causes the main fold of the tape to be reversed and the previously folded edge portions to be turned inwardly. The material, after being trimmed to the extent desired, passes between the main folds of the tape and then, with the binding tape in position, is moved by the cloth feed under the rear portion of the presser foot where the material plies and the tape folds are stitched in the usual manner. The folder R has a horizontal rear extension R5, which includes a transversev slot Rs through which a screw R" passes into engagement with the needle plate and by whicharrangement, the folder may be moved laterally relative to the needle to thereby regulate the position of the tape relative to the trimmed edge of the material. Other forms and sizes of folders may be readily substituted for the folder illustrated. A short vertical guard O9 on the presser foot adjacent the needle opening O8 assists in maintaining the binding tape in its desired position relative to the material. An inclined slot N2 is formed in the rear wall of the guard N and through which the operator can insert a suitable tool into a corresponding slot R4 in the folder to assist the initial passage of the tape through the folder R.

The construction and general mode of operation of the machine and particularly of the improvements described is evident from the foregoing description. The movements'of vthe knife E, needle A5, feed D4 and rotary hook D' are synchronized and effect a high speed trimming and binding operation on the material. As the surplus material istrimmed from the cloth, it is quickly disposed of and prevented from returning into the path of operation by the various guard members. The cutting position and extent of the cutting stroke of the movable knife can be easily regulated Within certain limits for different conditions of operation. The employment of a vertically reciprocable knife and the driving connections described provide a highly compact, simple and effective trimming mechanism, and permit the inclusion of substantially all of the movable driving parts within the head. The relative arrangement of the trimming knives, folder, and stitching mechanism described is particularly advantageous, enabling the operator to observe the successive operations with ease, while maintaining the range of movement and positions of the parts in the restricted space available. The described construction of the knife bar driving connections effects a positively operating arrangement, which may be thrown in and out of operation by the operator without loss of time due to improper or inoperative connections. The adjustable knife guide insures the necessary close contact between the stationary and movable knives in operation.

In the foregoing description the words front, rear, inner, and outer and corresponding terms have been repeatedly referred to in describing the construction and location of the various parts. These terms are used relative to the position of the operator, i. e., the front and rear sides of the machine are, respectively, adjacent to and opposite from the operator; while inner and outer refer, respectively, to points toward the standard and head ends of the machine.

While in accordance with the provisions of the statutes, I have illustrated and described the best form of embodiment of my invention now known to me, it will beapparent to those skilled in the art that changes may be made in the form of the apparatus disclosed without departing from the spirit of my invention as set forth in the appended claims and that in some cases certain features of my invention may be used to advantage without a corresponding use of other features.

Having now described my invention, what I claim as new and desire to secure by Letters Patent isz- 1. In a sewing machine having an overhanging arm, an enlarged head at the outer end of said arm and a needle plate arranged below said head, the combination with a drive shaft axially arranged in said arm, of a fixed trimming knife associated with said needle plate, a vertically reciprocable needle and needle bar, mechanism operatively connecting said needle bar and drive shaft, a cooperating vertically reciprocable trimming knife positioned in front of and at one side of said needle, an eccentric mounted on said drive shaft at the inner side of said mechanism, a vertically reciprocable knife bar, and mechanism substantially fin'cluded in said head operatively connecting said eccentric and knife bar.

2. In a sewing machine having an overhanging arm, an enlarged head at the outer end of said arm and a needle plate arranged below said head, the combination with a drive shaft axially arranged in said arm, of a fixed trimming knife associated with said needle plate, a vertically reciprocable needle and needle bar, mechanism operatively connecting said needle bar and drive shaft, an eccentric mounted on said drive shaft at the inner side of said mechanism, a vertically reciprocable knife bar mounted in the lower end of said head in the rear of said needle bar, mechanism operatively connecting said eccentric and knife bar, a knife carrier vertically and horizontally adjustable on the lower end of said knife bar and extending forwardly of said needle, and a vertically arranged trimming knife vertically and horizontally adjustable in said carrier forwardly of said needle and cooperating with said fixed knife.

3. In a sewing machine having an overhanging '.arm, an enlarged head at the outer end of said arm, and a needle plate arranged below said head, the combination with a drive shaft axially arranged in said arm, of a vertically reciprocable needle and needle bar ecoentrically connected to said drive shaft, a fixed trimming knife associated with said needle plate, a cooperating vertically reciprocable trimming knife, a vertically reciprocable knife bar connected to said movable knife, an eccentric mounted on said drive shaft at one side of said needle bar eccentric, mechanism operatively connecting said second eccentric and knife bar, said movable knife being arranged substantially in front of said needle, and a vertical guard member associated with said trimming knives and arranged to deflect and dispose of the material removed by said knives.

4. In a sewing machine having an overhanging arm, an enlarged head at the outer end of said arm, and a needle plate arranged below said head, the combination with a main drive shaft axially arranged in said arm, of a xed trimming knife associated with said needle plate, a cooperating vertically reciprocable trimming knife, means operatively connecting said reciprocable trimming knife and said drive shaft, a presser foot at one side of said reciprocable knife, and a guard member carried by said presser foot and extending along and adjacent to the cutting edge of said fixed knife.

5. In a sewing machine having an overhanging arm, an enlarged head at the outer end of said arm, and a needle platearranged below said head, the combination with a main drive shaft axially arranged in said arm, of a fixed trimming knife associated with said needle plate, a reciprocable needle and needle bar, a vertically reciprocable trimming knife at the inner side of and in front of said needle, means for operatively connecting said reciprocabletrimming knife and said drive shaft, a presser foot at the outer side of said reciprocable knife, and a guard adjustably mounted on the forward end of said presser foot and extending rearwardly along the inner face of said reciprocable knife.

6. In a sewing machine having an overhang-z edge of said reciprocable knife, a presser foot at one side of said reciprocable knife, and a second vertical guard member carried by said presser foot and extending along and adjacent tothe cutting line of said knives and cooperating with said first mentioned guard member to guide the material cut oif by said knives.

7. In a sewing machine having an overhanging arm, an enlarged head at the outer end of said arm, and a needle plate arranged below said head, the combination with a main drive shaft axially arranged in said arm, of a fixed trimming knife associated with said needle plate, a cooperating vertically reciprocable trimming knife,

means operatively connecting said reciprocable trimming knife to said drive shaft, a vertical guard member adjacent to and at one side of said reciprocable trimming knife, and an adjustable knife guide block mounted on said guard member with its outer end arranged to contact with the inner face of said reciprocable trimming knife du'ring the reciprocating movements of the latter.

mounted on said drive shaft at one side of said needle bar eccentric, mechanism carried by said second eccentric and substantially included within said head for operatively connecting said second eccentric and knife bar, said movable knife being arranged substantially in front of said needle, and a binding tape folding device positioned on said needle plate at the rear of said fixed knife and with its tape outlet end in front of said needle.

9. In a rotary hook sewing machine having an overhanging arm, an enlarged head at the outer end of said arm, a needle plate arranged below said head. and a rotary hook and hook shaft below said needle plate, the combination with a drive shaft axially arranged in said arm, of a vertically reciprocable needle and needle bar eccentrically connected to said drive shaft, a fixed trimming knife associated with said needle plate, a cooperating vertically reciprocabletrimming knife, a vertically reciprocable knife bar adjustably connected to said movable knife, an eccentric mounted on said drive shaft at one sideV of said needle bar eccentric, mechanism operatively connecting said second eccentric and knife bar, said movable knife being arranged substantially in front of said needle, a vertical guard member associated with saidtrimming knins and arranged to deflect and dispose of material removed by said knives, a binding tape folding device positioned at the Irear side ,of said guard member with its tape outlet end in front of said needle, and registering openings in said guard member and folding device for the insertion of a tape advancing tool.

MICHAEL McCANN.

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