US3436999A

US3436999A - Stripping cutters for sewing machines

Info

Publication number: US3436999A
Authority: US
Inventors: Richard Lewis; Paul D Pryor
Original assignee: Glamorise Foundations Inc
Current assignee: Glamorise Foundations Inc
Priority date: 1964-09-08
Filing date: 1967-07-03
Publication date: 1969-04-08
Anticipated expiration: 1986-04-08
Also published as: FR1455438A; NL6511732A; DE1485161A1

Description

April 8, 1969 R. LEWIS ET AL STRIPPING CUTTERS FOR SEWING MACHINES Sheet 4 of 4 Original Filed Sept. 8, 1964 Reflective Surface of Work Non-reflecflve 2% Surface of Table 24 .mwm R m N W0 NR ML U &A RP

April 8, 1969 wls ET AL 3,436,999

STRIPPING OUTTERS FOR SEWING MACHINES ori inal Filed Sept. 8, 1964 Sheet 2 of 4 INVENTORS= RICHARD LEWIS PAUL D. PRYOR Sheet R. LEWIS ETAL STRIPPING CUTTERS FOR SEWING MACHINES April 8, 1969 Sriginal Filed Sept.

INVENTORS RICHARD LEWIS PAUL D. PRYOR wa April 8, 1969 R. LEWIS ET AL. 3,436,999

STRIPPING CUTTERS FOR SEWING MACHINES Shet Qriginal Filed Sept. 8. 1964 INVENTORS= RICHARD LEWIS PAUL o. PRYOR IIOS' FF 7- United States Patent Office 3,436,999 Patented Apr. 8, 1969 US. Cl. 83561 Claims ABSTRACT OF THE DISCLOSURE A sewing machine attachment for automatically cutting stripping between individual pieces of work passing from the presser foot of the machine. The attachment consists of a guillotine type cutter with a power actuated cutter blade coacting with a rotatable impact receiving roller.

This application is a division of our copending application Ser. No. 394,668, filed Sept. 8, 1964, now Patent No. 3,329,113 dated July 4, 1967.

Our aforesaid copending application discloses an attachment for industrial sewing machines which repeatedly perform a particular sewing operation on identical, individual pieces of work, such work pieces passing from the presser foot of the sewing machine in a continuous manner with each work piece being connected to the next by what is generally known as stripping. The attachment comprises a guillotine type cutter disposed adjacent the presser foot, the cutter being power actuated automatically by light-responsive electrical means which detects the flow of work pieces from the presser foot.

The present application concerns itself particularly with the guillotine type cutter which includes a reciprocable cutter blade coacting with impact receiving means of a novel construction, the principal object of the invention being to substantially prolong the useful life of the cutter blade while the impact receiving means requires replacement only at infrequent intervals.

This object is attained by utilizing impact receiving means in the form of a rotatably mounted roller which turns slightly with each impact of the blade and thus presents a continually changing portion thereof to impact by the blade, whereby wear of the roller is considerably minimized and useful life of the blade is substantially prolonged.

This invention relates to new and useful improvements in attachments for industrial sewing machines which repeatedly perform a particular sewing operation on identical, individual pieces of work, such work pieces passing from the presser foot of the sewing machine in a continuous manner with each work piece being connected to the next by what is generally known as stripping.

The stripping may be in the form of sewing thread, tape, elastic, lace, edge binding, et cetera, applied to the work pieces by the sewing machine, the leading edge of each work piece being spaced somewhat along the running length of the stripping from the trailing edge of the preceding work piece.

After a sewing operation of this type it is, of course, necessary to separate the individual work pieces by cutting the stripping therebetween, and if the cutting operation is performed manually, a considerable loss of time and effort is involved.

It is, therefore, the principal object of the invention to save such lost time and effort by automatically cutting the stripping between the work pieces as they pass from the presser foot of the sewing machine. As such, the invention provides an electrically actuated cutting apparatus disposed adjacent and rearwardly of the sewing machine presser foot for severing the stripping between individual work pieces in an automatic, instantaneous manner so that the flow of work through the sewing machine need not be interrupted in order for the stripping to be cut.

Also, the invention provides light-responsive electrical means for detecting the flow of work in terms of spaces between the trailing and leading edges of the work pieces, such electrical means controlling the operation of the cutting apparatus so that the stripping is cut at appropriate, selected intervals in an automatic fashion.

As another feature, the electrical control means may be set so that the stripping is cut selectively at the leading edge of each work piece, or at the trailing edge, or at both leading and trailing edges.

As another feature, the electrical control means may be adjusted in terms of relationship of the work pieces to the cutting apparatus so that the stripping may be cut beyond the leading and/or trailing edges of the work pieces, in instances where it is desirable to have the stripping project beyond such edges.

As another feature, the electrical control means embodies a manually operable switch for actuating the cutting apparatus independently of the light-responsive automatic control, when for some reason a manual control is desirable.

Still another feature of the invention resides in the structure of the cutting apparatus itself, as distinguished from its electrical and manual controls, and particularly in novel means for absorbing the impact of the cutter blade so that the useful life of the blade is substantially prolonged while the impact absorbing means requires replacement only at infrequent intervals.

As still another feature, the arrangement of the invention is such that it is readily applicable as an attachment to conventional sewing machines of various types.

With the foregoing more important object and features in view and such other objects and featuress as may become apparent ts this specification proceeds, the invention will be understood from the following description taken in conjunction with the accompanying drawings, wherein like characters of reference are used to designate like parts, and wherein:

FIGURE 1 is a side elevational view of the cutting apparatus of the invention;

FIGURE 2 is an elevational view, taken in the direction of the arrow 2 in FIG. 1 and also showing the power pack and foot control used in this invention;

FIGURE 3 is a side elevational view of the cutting apparatus with its mounting omitted and its housing cover shown in section;

FIGURE 4 is a fragmentary sectional view, taken substantially in the plane of the line 4-4 in FIGURE 3;

FIGURE 5 is a fragmentary sectional view, taken substantially in the plane of the line 5-5 in FIGURE 1;

FIGURE 6 is an enlarged, fragmentary vertical sectional view of the cutter mechanism;

FIGURE 7 is a sectional detail, taken substantially in the plane of the line 77 in FIGURE 6;

FIGURE 8 is a fragmentary plan view of the plate and roller of the cutter mechanism;

FIGURE 9 is a fragmentary sectional detail, taken substantially in the plane of the line 99 in FIGURE 8;

FIGURE 10 is an enlarged perspective view of the work guard;

FIGURE 11 is a wiring diagram of the electrical components of the invention;

FIGURE 12 is a diagrammatic illustration of the action of the photoelectric cell;

FIGURE 13 is a diagrammatic illustration of work pieces in relation to light reflecting areas affecting the photoelectric cell;

FIGURE 14 is a fragmentary side elevational view, similar to that in FIG. 1, but showing a modified embodiment of the invention;

FIGURE 15 is a fragmentary plan view of the machine table shown in the embodiment of FIGURE 14;

FIGURE 16 is a wiring diagram of the electrical components used in the modified embodiment of FIGS. 14, 15, a portion of the circuit not shown being the same as in FIG. 11;

FIGURE 17 is a fragmentary plan view of the machine table in another modified embodiment of the invention;

FIGURE 18 is a fragmentary sectional view, taken substantially in the plane of the line 1-8--18 in FIG. 17; and

FIGURE 19 is a wiring diagram of the electrical components used in the modified embodiment of FIGS. 17, 18, a portion of the circuit not shown being the same as in FIG. 11.

Referring now to the accompanying drawings in detail, more particularly to FIGS. l-13 inclusive which show one embodiment of the invention, the general reference numeral 21 designates the cutting apparatus such as may be applied to any conventional sewing machine having the usual needle 22 and presser foot 23 cooperating with the machine table 24. The numeral 25 designates a face plate by which the apparatus may be attached to the head of the sewing machine, as by the screws 26, of if desired, the face plate may be omitted and the device attached directly to the machine head by the screws 27, in which instance the element 25 may be regarded as the machine head itself. A mounting plate 28 is secured by the screws 27 to the face plate (or machine head) 25 and projects rearwardly therefrom to support the cutting device 21. The latter includes a U-shaped housing 29 with open sides and back which are closed by a removable U-shaped cover 30, held in place by suitable screws 31. One side of the cover 30 is recessed as at 30 to provide clearance for the mounting plate 28 which is secured to the base portion 29 of the housing 29 by the screws 32.

Contained in the housing 29 is a solenoid 33 which is mounted on the base portion 29 by the screws 34 and has a reciprocable armature 35. The lower end of the armature is rigidly connected to a strap-like slide 36 which is reciprocable in a slide support or guide 37, the latter having an angulated upper end portion secured as at 38 to the housing base 29' and also having a removable cover 39 held in place by the screws 40, as is best shown in FIG. 7. A stud 41 is carried by the slide 36 and projects through a slot 42 formed in the cover 39. A tension spring 43 is connected at one end thereof to the stud 41 and at its other end to a similar stud 44 depending from the housing base 29'. The spring 43 serves to draw the slide 36 upwardly in the guide 37 when the solenoid 33 is not energized. The lower end of the slide 36 carries a cutter blade 45 which is removably held in place by a clamp 46.

Ordinarily, the cutter blade 45 would cooperate with a simple backing plate or reaction plate 47 held in place on the machine table 24 by suitable screws 48, but repeated impact of the sharp blade against the plate would cause both the blade and the plate to wear out prematurely. To avoid such premature wear, the invention provides an impact roller 49 which is rotatably positioned in a recess 50 formed in the plate 47, the recess having upwardly convergent side walls as shown in FIGS. 6 and 9 so as to retain the roller in place. The roller is preferably made of somewhat softer material than the blade 45 so that the roller rather than the blade is subjected to wear, but inasmuch as the roller is rotatable, it turns slightly with each impact of the blade and thus presents a continually changing portion thereof to impact by the blade, whereby wear of the roller is considerably minimized and frequent replacement of the roller is unnecessary. As will be apparent from FIG. 6, the top of the roller 49 is substantially flush with the upper surface of the plate 47 and the cutter blade 45 reciprocates in an inclined plane which intersects the roller slightly rearwardly of the roller axis, so that when the blade 45 comes in contact with the roller, the blade is prevented from springing rearwardly by the upper edge 50' at the back wall of the recess 50. Also, the blade upon impact is prevented from springing forwardly by the rising curvature of the roller, and assurance is thus had that the blade impacts the roller with microscopic precision, without any incidental springing, flexing or vibration of the blade taking place. Moreover, by contacting the roller rearwardly of the roller axis, each impact of the blade causes the roller to turn slightly, in a counterclockwise direction as viewed in FIG. 6, so that a fresh surface portion of the roller is presented after each impact for the next, as already mentioned. The plate 47 is provided with slots 51 to receive the attaching screws 48, whereby the position of the plate and roller 49 may be adjusted forwardly and rearwardly in relation to the cutter blade 45 to obtain the desired contact of the blade with the roller.

The forward end portion of the plate 47 is sloped as at 47 so that work moving rearwardly from the presser foot 23 of the sewing machine may pass easily over the plate. In order to prevent the work from becoming entangled with the slide 36 and to guide the work on its passage between the blade 45 and the roller 49, a work guard 52 is disposed forwardly of the slide 36 above the plate 47. As shown in FIG. 10, the guard 52 is substantially U-shaped and has a collar 53 equipped with a set screw 54, whereby it may be fastened to the leg 23 of the presser foot 23, as will be clearly apparent from FIG. 1.

The individual pieces of work turned out by the sewing machine have stripping thereon, such as for example, tapes, elastic bands, simple stitching, et cetra, and the work pieces pass rearwardly from the presser foot 23 in a continuous chain fashion, being connected to one another by such stripping which not only extends along the work pieces but also spans relatively small spaces which exist between the trailing edge of each work piece and the leading edge of the next. This is illustrated diagrammatically in FIG. 13, where the individual work pieces are shown at 55, each having a leading edge 56 and a trailing edge 57, with the stripping 58 extending along the work pieces and bridging the spaces between the trailing and leading edges thereof. The work pieces thus pass from the sewing machine in a continuous manner, connected together by the stripping, and the purpose of the apparatus of the invention, of course, is to cut the stripping between the work pieces so that the work pieces become separate, individual entities. The direction of travel of the work is shown by the arrow 59 in FIG. 13, this being rearwardly from the presser foot 23 over the cutter impact roller 49 as seen in FIG. I, and the arrangement of the invention is such that the solenoid 33 of the cutter may be automatically energized so that the cutter blade 45 my cut the stripping selectively at the trailing edge 57 of each work piece, or at the leading edge 56 of each work piece, or at both the leading and trailing edges of each work piece, as desired. Also, adjustment means are provided for cutting the stripping at a point between the trailing and leading edges of the work pieces, thus leaving portions of the stripping to project beyond the work piece edges, when such projections of the stripping are desirable.

A power supply and control pack 60 is provided in conjunction with the cutter apparatus 21 and may be conveniently placed on or adjacent the sewing machine, the power pack having a plug connection 61 to a suitable source of alternating current, for example, V. AC. The power pack is in circuit with the solenoid 33 of the cutter and also with a photoelectric cell 62 which responds to the flow of work pieces from the presser foot to actuate the cutter, as will be hereinafter described. The cell 62 is mounted by a suitable bracket 63 on the face plate (or machine head) 25, the mounting preferably being vertically adjustable so that the cell may be raised or lowered relative to the machine table 24. The cell 62 is optically oriented to one side of the plate 47 against the machine table 24, which table in this instance either has a substantially dull, non-reflective surface or is provided with a dull, non-reflective coating at least on that portion of its surface which is in optical alignment with the photoelectric cell 62.

At this point it may be explained that the embodiment of the invention now being described is intended to be used on work of white or other light color which has good light reflecting properties, so that the intensity of light needed to energize the photoelectric cell 62 need not be more than the ambient light in the vicinity of the sewing machine, reflected by the light colored work pieces to the cell. Under such conditions the aforementioned space between the trailing edge of one Work piece and the leading edge of the next permits the dull, non-reflective surface of the machine table to become exposed, thus interrupting the reflection of ambient light to the cell and deenergizing the latter. The term ambient light as used herein refers not only to general illumination available in the vicinity of the machine, but also to light from a conventional work illuminating lamp which is commonly provided on the machine head itself, as well as to any special lamp such as may be used for reflection of light rays by the work pieces to the photoelectric cell.

As will be apparent from FIG. 12, the ambient light reflected by a Work piece 55 passes to the cell 62 in a conical beam 65, the base of which is a circular or oval area 66 which the cell 62 sees either on the reflective work piece or on the non-reflective machine table 24, as diagrammatically shown in FIG. 13. For reasons hereinafter explained, it is desirable to vary the diameter or width of the cell seeing area 66, this being attained either or both, by raising or lowering the cell 62 relative to the table 24 by the bracket means 63, and/ or adjusting a tubular shield 67 which is slidably positioned on the cell 62 so that the downward spread of the conical beam 65 may be increased or decreased by respectively raising and lowering the shield 67 relative to the cell. For illustrative purposes, the seeing area 66 of the cell is substantially larger or wider than the area 66 as shown in FIG. 13.

Turning again to the aforementioned power supply and control pack 60 and with reference to FIGS. 2 and 11, the pack has a suitable housing or casing 68 which contains various electrical components including an onand-otf master switch 69, a pilot lamp 70, a three-position selector switch 71, and an on-and-off switch 72 for the photoelectric cell 62.

One side 73 of the circuit from the power supply 61 flows through the master switch 69 to two

contacts

74, 75 of a control relay 76 which also has two other contacts 77, 7 S and a pair of switch members 79, 80 operable by a solenoid 81, the relay being spring biased so that when the solenoid is not energized, the switch members 79, 80 engage the

respective contacts

74, 78 as shown in FIG. 11, but when the solenoid is energized, the switch members engage the respective contacts 77, '75. The

contacts

77, 78 are connected as at 82 to the solenoid 83 of a cutter actuating relay 84, the solenoid 83 being in circuit with the second side 85 of the power supply 61. The solenoid 33 of the cutter mechanism is connected in series with the switch 86 of the relay 84 to the circuit sides 73, 85, the switch 86 being open When the relay is not energized.

A resistor 87 and a diode 88 are provided in the circuit side 85 for energizing the relay solenoid 33 by direct current. The pilot lamp 70 is bridged across the circuit sides 73, so that it is energized when the master switch 69 is closed. The solenoid 81 of the relay 76 is connected through a diode 89 to the circuit side 73 and is also connected as at 90 to the circuit side 85, the connection 90 being in series through the photoelectric cell 62 and cell control switch 72. The connection 90 also includes a manually operated switch 91 which is bridged in parallel across the cell 62 and switch 72. The switch 91, also shown in FIG. 2, is normally open and may be placed under the sewing machine for convenient actuation by the operators foot. A resistor 92 and a capacitor 93 are provided for the solenoid 81 of the relay 76, as shown.

The three-position selector switch 71 has two sets of

contacts

94, 95, 96 and 97, 98, 99 with a movable con tact member 100 so arranged that when the contact member is in a central position it bridges the

contacts

94, 95 on one side and the contacts 98, 99 on the other. In the left hand position of the switch (as viewed in FIG. 11), the member bridges the con-tacts 97, 98 only, and in the right hand position it bridges the

contacts

95, 96 only. The

contacts

94, 96 are connected to the circuit side 85 through a capacitor 101, while the contact 98 is connected to the same circuit side through a capacitor 102. The contact 95 is connected to the switch member 79 of the relay 76, while the contacts 97, 99 are connected to the switch member 80 of the same relay.

In operation, the master switch 69 is closed and the pilot lamp 70 becomes energized. When there is no work piece under the photoelectric cell 62 to reflect ambient light to the cell, the resistance of the cell is so high that no appreciable current flows through the connection 90 to the solenoid 81 of the relay 76, and the switch members 79, 80 of that relay are in the position shown in FIG. 11. In this position, current flows from the circuit side 73 through the relay switch member 79 to the contact 95 of the selector switch 71, and assuming the selector switch to be in its central position as shown, the contact 95 is bridged to the contact 94 by the member 100 and the capacitor 101 becomes charged.

When a reflective work piece comes into position under the photoelectric cell 62 and reflects ambient light to the cell, the resistance of the cell is lowered so that current flows through the connection 9 to energize the solenoid 81 of the relay 76. As this occurs, the switch member 79 is brought against the contact 77 and the member 80 against the contact 75. Engagement of the member 79 with the contact 77 permits the electrical charge stored in the capacitor 101 to flow through the connection 82 to the solenoid 83 of the relay 84, thus closing the relay switch 86 and energizing the solenoid 33 of the cutter mechanism which instantly propels the cutter blade 45 toward the impact roller 49 to sever the stripping 58 at the leading edge 56 of the work piece 55 (see FIG. 13). The discharge of current from the capacitor 101 to the relay solenoid 83 is instantaneous as is energization of the cut ter solenoid 33, so that the cutter blade 45 may be quickly retracted by the spring 43 as soon as energization of the solenoid 3'3 ceases. In the meantime, the presence of the work piece under the photoelectric cell 62 still continues to cause the solenoid 81 of the relay 76 to remain energized, and while the switch member 89 is still against the contact 77, engagement of the switch member 80 with the contact 75 permits current to flow from the circuit side 73 through the contacts 98, 99 bridged by the member 100, so as to charge the capacitor 102. Ultimately, when the work piece moves from under the photoelectric cell, energization of the relay solenoid 81 ceases and the contact members 79, '80 are returned to the initial position shown in FIG. 11. As soon as this occurs, the electrical charge stored in the capacitor 102 flows through the member 80 and connection 32 to energize the relay solenoid 83 and the cutter solenoid 33, thus again causing the cutter blade 45 to sever the stripping, but this time at the trailing edge 57 of the work piece. In the meantime, en-

gagement of the switch member 79 with the contact 74 again causes the capacitor 101 to be charged in readiness for the next cycle of operation.

If the three-position selector switch 71 is moved to its right hand position wherein the member 100 bridges the

contacts

95, 96 only, the first half of the operation as above described is the same in that the capacitor 101 is discharged when the work piece comes under the photoelectric cell and the stripping is cut at the leading edge of the work piece. However, in this right hand position of the switch 71, charging of the capacitor 12 through the contact 98 is not possible and accordingly, when the work piece moves from under the photoelectric cell and the relay 76 returns to its initial position, there is no charge in the capacitor 102 to energize the relay 84 and cutter solenoid 33 to cut the stripping at the trailing edge of the work piece. Thus, with the selector switch 71 in its right hand position, the stripping is cut only at the leading edge of the work pieces. Conversely, if the switch 71 is in its left hand position wherein the member 100 bridges the contacts 97, 98 only, charging of the capacitor 101 is not possible and the stripping is cut only at the trailing edge of the work pieces, as will be readily understood.

Referring again to the diagrammatic illustration in FIG. 13, the cutter may be actuated when the work piece 55 enters the seeing area 66 of the photoelectric cell, or when it leaves the seeing" area, or both when it enters and leaves. As already explained, the efiective diameter or width of the seeing area (66 or 66') may be varied by raising or lowering the shield 67 relative to the photoelectric cell 62, or by raising or lowering the entire cell by the bracket means 63. This variation of diameter or width of the seeing area affords an adjustment which permits the cutter to sever the stripping at the trailing and leading edges of the work pieces, regardless of the extent of spacing between adjacent work pieces within limits of variation of the efiective size of the seeing area. Also, if only one cut of stripping is made for each work piece, either at the leading edge or at the trailing edge the cut may be made so that it is intermediate the leading and trailing edges and the stripping projects from each work piece beyond both such edges. This may be done by simply enlarging the seeing area of the photoelectric cell, for example as at 66', so that the cutter severs the stripping as indicated by the line 103 in FIG. 13.

It may be noted at this point that inasmuch as the cutter is actuated instantly by an electric charge stored in the capacitors (101 or 102) rather than directly by the photoelectric cell 62, use of the selector switch 71 is facilitated which permits energization of the cutter at either or both the leading and trailing edges of work pieces. Also, very rapid cutting action is possible, several cutting strokes per second if need be, so that the work pieces 55 may be closely spaced along the stripping 58 with full assurance that the cutter will cut stripping at the leading edge of each work piece, immediately after cutting at the trailing edge of the preceding one.

The aforementioned foot control switch 91 which is bridged in parallel across the photoelectric cell 62 and switch 72 may be used by the operator of the sewing machine to actuate the cutter independently of the photoelectric cell, except when the cell is energized by light reflected from a work piece under the cell. In such event, the energized cell 62 already causes energization of the relay 76, so that manual closing of the foot switch 91 does not make any change. However, when there is no work piece under the cell 62 and the latter is inactive, the relay 81 may be manually energized through the foot switch 91 to cut stripping between work pieces at the operators will. The cell control switch 72, in series with the cell 62, is nomally closed, but may be opened when desired so as to render the cell 62 inactive regardless of presence or absence of work pieces under the cell, in which instance the operation of the cutter may be controlled manually and solely by the foot switch 91.

Reference is now drawn to FIGS. 14, 15 and 16 which show a modified embodiment of control for the cutter apparatus, the cutter apparatus itself being the same as at 21 in FIGS. 110 and also utilizing the solenoid 33, the relay 84, the selector switch 71, the

capacitors

101, 102, resistor 87, diode 88 and the relay 76, all as disclosed in the upper portion of FIG. 11 already described. However, in place of the photoelectric cell 62, the modified arrangement utilizes a plate-shaped selenium cell or so-called solar cell 105 which is capable of producing weak electric current when subjected to light. The cell 105 is suitably mounted on the sewing machine table 24 at one side of the cutter impact plate as shown in FIGS. 14, 15, and is adapted to be energized by a light beam from a lamp 106 mounted by the bracket 63 on the machine head (or face plate) 25, the lamp 106 thus occupying the position held by the cell 62 in the embodiment of FIGS. 113. It will be understood that when the lamp 106 is energized and its beam can pass through spaces between the work pieces to the cell 105, electric current will be generated by that cell. On the other hand, when a work piece interrupts the light beam by its presence between the lamp and the cell, no current will be generated. Thus, while the embodiment of FIGS. l-13 is suitable for use with Work of light color which is capable of reflecting ambient light to the photoelectric cell 62, the embodiment of FIGS. 14-16 may be used with work of any color, inasmuch as the electric control of the cutter apparatus responds not be light reflection, but to passage of a light beam to the current generating cell 105.

The solar cell 105 is connected to the base and emitter of a transistor 107 for amplification of the collector circuit 108 through the solenoid 109 or a relay 110, the switch 111 of which serves to energize the relay 76 in the same manner as the aforementioned cell 62 in the embodiment of FIGS. 113. The collector circuit 108 of the transistor 107 includes a resistor 112, capacitors 113 and a diode 114 for direct current operation of the relay solenoid 109, the circuit 108 being powered by a transformer 115 connected to the aforementioned circuit sides 73, 85 of the power supply 61. The lamp 106 is also powered by the transformer 115 at a step-down voltage.

In operation, the master switch 69 is closed and the lamp 106 becomes energized by the transformer 115. Assuming that a work piece has just moved from above the solar cell 105, the light beam from the lamp 106 is free to reach the cell 105, causing the latter to become energized and to produce a weak electric current which triggers the transistor 107. Strong current then flows in the collector circuit 108 through the solenoid 109 of the relay 110, causing the switch 111' of that relay to close and energize the solenoid 81 of the relay through the connection 90, as will be apparent from FIG. 16. As this occurs, the capacitor 101, which has been charged during a previous cycle of operation, is discharged through the switch member 79 and contact 77 (see FIG. 11), thus energizing the cutter solenoid 33 and causing the cutter to sever stripping at the trailing edge of the work piece which has just moved from above the solar cell 105. Also, the capacitor 102 becomes charged through the contact 75 and the switch member 80.

With the light beam from the lamp 106 falling upon the cell 105, the cell and the

relays

110, 76 continue to remain energized until the next in line work piece comes into position above the cell 105. This interrupts the light beam from the lamp 106, the cell ceases to generate current, the relay switch 111 opens and the solenoid 81 of the relay 76 is tie-energized. This discharges the capacitor 102 through the contact member and contact 78 and the cutter solenoid 33 is again energized, the cutter now severing the stripping at the leading edge of the work piece which has come into position above the cell 105. Also, the capacitor 101 becomes charged through the contact 74 and switch member 79 in readiness for the next operational cycle when the work piece moves from above the cell 105 and energization of the cell by the light beam again takes place.

Of course, the stripping may be cut only at the leading edge or only at the trailing edge of the work pieces by moving the selector switch 71 from its central position to either left or right, substantially as already explained in connection with FIG. 11. However, it is to be noted that when the photoelectric cell 62 of FIG. 11 is used, the solenoid 81 of the relay 76 is energized only When a work piece is in position under the cell, but when the solar cell 105 and the lamp 106 of FIG. 16 are used, the relay 76 is energized only when there is no work piece in a comparable position. Accordingly, in the latter arrangement the operation of the relay 76 is reversed with respect to the former arrangement, the capacitor 101 providing power for cutter actuation at the trailing edge and the capacitor 102 at the leading edge when using the solar cell 105, and vice versa when using the photoelectric cell 62. Thus, when using the cell 105, the selector switch 71 is moved to the left for cutting at the leading edge only, but when using the cell 62 the switch is moved to the right for the same purpose.

The foot switch 91 may be used with the circuit of FIG. 16 for manual rather than automatic control of the cutter, but inasmuch as the automatic switch 111 is already closed when there is no work piece above the solar cell 105, closing of the foot switch 01 in parallel with the switch 111 would not produce any cutting action. Accordingly, the switches 91 and 111 are connected to a manually operable, single pole, double throw switch 116 on the circuit side 85, the switch 116 permitting energization of the solenoid 81 of the relay 76 either automatically by the relay 110 or manually by the foot switch 91. The cell control switch 72 of FIG. 11 is thus not required and its position on the power pack 60 may be occupied by the switch 116. Also, since in the circuit of FIG. 16 the full current strength from the power source 61 flows through the solenoid 81 of the relay 76, the resistor 92, the capacitor 93 and the diode 89 of FIG. 11 are not needed in the embodiment of FIG. 16.

FIGS. 17, 18 and 19 illustrate another modified arrangement which is very similar to that already described in connection with FIGS. l4-l6 but embodies a cutter actuating adjustment which takes into consideration the position of work pieces relative to the position of the cutter blade. As such, this embodiment performs a function which is somewhat similar to that served by adjustment of the seeing area 66 of the photoelectric cell 62 described in connection with FIGS. 12 and 13, but is more flexible and broader in scope inasmuch as it pro vides two adjustable entities rather than one, as will be presently apparent.

The embodiment of FIGS. 17-19 utilizes two separate solar cells 105, 105' mounted on the machine table 24 at one side of the impact plate 47, the cell 105 being disposed forwardly and the cell 105' rearwardly of the cutter blade 45 and both cells being adjustable toward and away from each other in the direction of travel of the work pieces. Two separate transistors 107, 107' and two

separate relays

110, 110 are connected to the

respective cells

105, 105, the collector circuit 108 of the transistor 107' and relay solenoid 109' being in parallel with the collector circuit 108 of the transistor 107 and relay solenoid 109 so that the two collector circuits may be independently energized. A single lamp 106 is sufficient for actuating the two solar cells. The switch 111 of the relay 110 is connected in series with the switch 111 of the relay 110 to the

circuit

85, 90, 73 of the relay solenoid 81, so that the relay 76 cannot become energized unless both switches 111 and 111 are closed.

In operation, when there is no work piece above the cells 105, 105', light from the lamp 106 energizes both cells, both

relays

110, 110 are energized, and current flows through the closed switches 111, 111', thus keeping the solenoid 31 of the relay 76 energized as already explained in connection with FIG. 16. When a work piece comes into position so that its leading edge covers the cell 105, the relay switch 111 is opened, the relay 76 is de-energized, and the cutter is actuated to sever stripping at the leading edge of the work piece. As the work piece continues to travel so that it covers the cell as well as the cell 105, the relay switch 111' is also opened, but without effect inasmuch as the circuit to the relay 76 is already broken by the open switch 111. When the trailing edge of the work piece clears the cell 105, the relay switch 111 closes, but also without effect inasmuch as the circuit to the relay 76 is still broken by the switch 111. Finally, when the trailing edge of the work piece clears the cell 105', the switch 111' is closed, thus completing the circuit to the relay 76 and actuating the cutter to sever stripping at the trailing edge of the work piece.

It will be apparent that inasmuch as the

cells

105, 105 may be moved toward or away from each other and to ward or away from the position of the cutter blade 45 therebetween, the timing of cutter actuation may be adjusted not only for different spacing of work pieces along the length of the stripping, but also for cutting of the stripping at different lengths beyond the leading and trailing edges of the work pieces when it is desired to have the stripping project beyond such edges.

The flat solar cells (105, 105) used in the embodiments of FIGS. 14-16 and 17-19 may be mounted unobtrusively on the top surface of the sewing machine table 24, or the table may be recessed for flush mounting of the cells, if so preferred. As examplified in FIGS. 17 and 18, the mounting recess 119 is elongated to permit adjustment of the cells toward and away from each other and is slotted through the machine table as at 120 to accommodate the wire connections to the cells. Any suitable means such as screws, or the like, may be used for locking the cells in an adjusted position.

As already mentioned with respect to all embodiments of the invention, the cell means which respond to the presence or absence of work pieces are located to function at one side of the impact plate 47, while the stripping by which the work pieces are connected together travels directly over the impact plate for severing by the cutter blade 45. While this arrangement is entirely satisfactory in most instances, particularly those where the work pieces project laterally to one side of the stripping only, there may be instances where the work pieces project laterally to both sides of the stripping and the oppositely projecting portions of their leading and/ or trailing edges are not in transverse alignment. For example, the leading edge portion of the work piece at one side of the stripping may be in advance of or behind the leading edge portion at the opposite side of the stripping, in which event a cell detector at only one side would not necessarily actuate the cutter at an appropriate moment in relation to the work. In such instances two cell detectors may be used in transverse alignment at opposite sides of the stripping, such cell detectors being electrically connected in parallel so that either one or the other may respond to the passage of the work piece for actuating the cutter at an appropriate moment. Since an arrangement of this nature involves merely a duplication of parts as disclosed in the various embodiments, an illustration thereof is not believed to be necessary.

While in the foregoing there have been described and shown the preferred embodiments of the invention, various modifications may become apparent to those skilled in the art to which the invention relates. Accordingly, it is not desired to limit the invention to this disclosure, and various modifications and equivalents may be resorted to, falling within the spirit and scope of the invention as claimed.

What is claimed as new is:

1. In a stripping cutter for sewing machines, the combination of a reciprocable cutter blade, means for reciprocating the same, a rotatable impact roller engageable by said blade, a recessed mounting member having said roller rotatably positioned in the recess thereof, an edge of said member adjacent and parallel to the axis of said roller constituting guide means for said blade to impact the roller between said guide means and the roller axis.

2. The device as defined in claim 1 wherein said recessed mounting member has an upper surface and the recess, said edge of the mounting member which constitutes said guide means for said blade existing at the junction of one of said convergent side walls with. the

upper surface of the mounting member.

3. The device as defined in claim 2 wherein the to'pjof said roller is substantially flush with the upper surface of said mounting member.

References Cited UNITED STATES PATENTS 1,236,508 8/1917 Wadhams 83-659 X 1 1,676,260 7/1928 Glidden 83--561 X 2,405,598 8/1946 Miller 83561 X 3,094,031 5/1963 {Reeber et 211. f 83902 X JAMES M. MEISTER, Primary Exam-ter.

US. 01. X.R. 83-635, 659, 679, 902