US3797422A

US3797422A - Work piece feeding device for sewing machines or the like

Info

Publication number: US3797422A
Application number: US00211455A
Authority: US
Inventors: K Sakawa
Original assignee: Brother Industries Ltd
Current assignee: Brother Industries Ltd
Priority date: 1970-12-24
Filing date: 1971-12-23
Publication date: 1974-03-19
Anticipated expiration: 1991-03-19
Also published as: NL7117717A; DE2164367A1; GB1365350A

Abstract

A feeding device for feeding a work piece to the throat plate of a sewing machines wherein a feed plate for feeding a work piece from its received position is kept floating relative to its support by resilient means, so that the work piece is smoothly supplied to the sewing machine.

Description

United States Patent [191 Sakawa 1 WORK PIECE FEEDING DEVICE FOR SEWING MACHINES OR THE LIKE [75] Inventor: Katsuaki Sakawa, Chiryu, Japan [73] Assignee: Brother Kogy Kabushiki Kaisha,

Nagoya-shi, Japan 22 Filed: Dec. 23, 1971 211 Appi. No.: 211,455

130] Foreign Application Priority Data Dec. 24, 1970 Japan 45-127573 Dec. 25, 1970 Japan 45125651 Dec. 26, 1970 Japan 45-138362 [56] References Cited UNITED STATES PATENTS 9/1970 Rovin et a1. ..1l2/121.11X

[ Mar. 19, 1974 3,616,093 10/1971 Teed 112/104 X 3,528,378 9/1970 Westhoff et a1. 112/121.15

3,513,792 5/1970 Rossler 112/121.15 3,156,206 11/1964 Hall et a1. 112/104 X 3,513,791 5/1970 Fuip 112/104 3,377,972 4/1968 Cohen et a1. 112/104 1,998,885 4/1935 Rosenthai 112/104 1,046,520 12/1912 White 112/104 2,560,186 7/1951 Piopper 112/113 X 2,548,692 4/1951 Vollman et a1. .1 112/113 X 3,561,381 2/1971 Weiss 112/114 3,552,336 1/1971 Brandriff 112/121.15

Primary Examiner-Geo. V. Larkin Attorney, Agent, or Firm-George B. Oujevoik 5 7 ABSTRACT A feeding device for feeding a work piece to the throat plate of a sewing machines wherein a feed plate 'for feeding a Work piece from its received position is 5 Claims, 14 Drawing Figures PAIENTEUIAR 19 I974 SHEET 1 0f 8 FIG.

PATENTED MR 1 9 I974 SHEET 2 [1F 8 mmmm 19 914 3 797L422 sum 3 UF a FIG. 3

PATENTEUIAR I 9 1914 SHEET 0F 8 HLU. mm

PATENTEU MR 19 I974 SHEET 5 [IF 8 WORK PIECE FEEDING DEVICE FOR SEWING MACHINES OR THE LIKE This invention relates to a work feeding device for sewing machines.

Where small pieces of material are attached to a suit such as a label, name, pockets and flaps or said attachments are sewn to the body of a suit using a conventional cycle sewing machine, the operation is performed by placing the work piece at a prescribed position on the underside o'fa lifted presser foot of the sewing machine and later bringing down the presser foot to have the work piece held to the bed surface and starting the machine for the required sewing.

However, the above-mentioned arrangement has the drawbacks that the operator himself has to place a work piece at a prescribed position on the underside of a lifted presser foot with considerable difficulty; in some cases it is necessary to make a number of attempts to obtain the proper location; failure of accurate location detracts from the'commerical value of the resulting suit; and the operator has to feed a work piece to the underside of the presser foot each time the aforesaid sewing operation is carried out and so finally feels annoyance and fatigue with the resultant decreased working efficiency.

It is accordingly an object of this invention to provide a work piece feeding device for a sewing machine or the like which 'allows the operator easy access to the machine to facilitate the feeding of a work piece or enables him to sew said work piece efficiently.

Another object of the invention is to provide a work piece feeding device permitting the smooth feeding of a work piece to the sewing machine.

Still another object of the invention is to provide a work piece feeding device equipped with a floating feed plate mounted on resilient means, so that even when there is a difference in heights of said feed plate and machine bed because of errors in designing and assembling the sewing machine and the work piece feeding device and fitting them to a table, the feed plate can slide back and forth smoothly on the bed surface compensating for such errors by floating; where there is sewn a work piece to a fabric mounted on the bed, the feed plate floats over the fabric even though the fabric may vary in thickness with different kinds of material or have folds or creases; and the feed plate intermittently passes over the connection between its support and machine bed or, even when both members are spaced relatively apart, provide a smooth reciprocating movement.

A further object of the invention is to provide work piece feeding device for an ordinary cycle machine, wherein this feed plate is kept in a floating condition, and the work piece can be readily pressed against the machine bed; when the feed plate is retracted to its original position, the work piece is still held on the under side of the presser foot; and on starting the machine, the work piece is forwarded further for sewing.

The present invention can be more fully understood from the following detailed description when taken in conjunction with the appended drawings, in which:

FIG. 1 is a perspective view of an ordinary cycle sewing machine and a work piece feeding device therefor placed on a table;

FIG. 2 is an enlarged fractional front view of the same; i

FIG. 3 is a longitudinal sectional view of the work piece feeding device with its cover taken off;

FIG. 4 is a plan view of FIG. 3;

FIG. 5 is an enlarged fractional sectional view of the resilient means for supporting the feed plate;

FIG. 6 is an enlarged front view of the actuating mechanism of the presser member;

FIG. 7 is a plan view of the same;

FIG. 8 illustrates the operation of the same;

FIG. 9 is a plan view of the presser foot of the sewing machine;

FIG. 10 is a side view of the same;

FIG. 11 is a perspective view of a work piece sewn by the machine;

FIG. 12 is a top view of a work piece conducted to the underside of the presser foot and pressed against the bed upon the fall of said foot;

FIG. 13 shows an electric circuit for controlling the operation of the work piece feeding device; and

FIG. 14 presents an electric circuit for controlling the operation of the sewing machine associated with that of said device.

Referring to FIGS. 1 and 2, numeral 2 is a machine table, and numeral 1 a cycle sewing machine of the known type mounted thereon. The frame 3 of the machine 1 has a bed 4 on which there is mounted a throat plate 5 to provide a work support surface. Numeral 6 is a needle rod recirpocating interlockingly with the arm shaft (not shown) of the machine 1. To the lower end of said arm shaft is fitted a needle 7. Numeral 8 is a presser foot mechanism disposed above the bed 4, said mechanism 8 being provided at the forward end with a presser foot 10 normally urged downward by a spring 9. The presser foot mechanism 8 is reciprocated lengthwise as well as crosswise by a cam disk 11 rotated jointly with the machine arm shaft to move a work piece such as a label together with the presser foot 10, thereby performing a cycle of sewing. Numeral 12 is a presser foot lifting bar fitted to the machine frame 3, said bar 12 being lifted when there is energized a presser foot solenoid l3 fitted to the underside of the table 2, thereby raising the presser foot 10. Rearward of the frame is provided a clutch mechanism 14 to bring the machine to rest.'When a start solenoid 15 is energized, clutch mechanism 14 actuates all the parts of the machine including the needle and cam. Once the solenoid 15 is energized, said clutch mechanism is mechanically held in an operating position by a latch 16. Even when the solenoid is deenergized, the clutch mechanism continues to keep the machine driven. Upon completion of one cycle of sewing, the latch 16 is operated by the cam disk 11 to release the stop mechanism, thereby bringing the machine to rest.

Numeral 17 represents a work piece feeding device so disposed as to face the side, particularly the presser foot 10 of the machine to feed a shaped work piece such as a label on to the bed thereof. Numeral 18 is a base screwed to the table 2 and provided on the underside with a control box 19 containing the later described electric circuit. On said base 18 is a support 20. The height of support 20 can be adjusted through .a support rod 21 held to the underside of said support 20 by a thumbscrew 22 in base engaging support rod 21. The support 20 is a substantially flatplate with both of its lengthwise edges raised upright. At the forward end of said support (the term forward end" means the left side of the drawing and the opposite right side thereof is referred to as the rear end) is fixed a support plate 23 by a screw 24 so as to have its forward end substantially engaging the throat plate 5 of the machine. On said support plate 23 is pivotally mounted a holder or actuating frame 26 so as to tend to pivot about a screw 25 penetrating the rear end of said raised side edges. Said holder 26 is further made, as shown in FIGS. 3 and 5, to float above the support 20 by being resiliently supported by a coil spring 29 stretched between the underside of the holder 26 and a thumbscrew 28 engaging a cylindrical spring support 27 projecting from the underside of said support 20. The force of said spring 29, that is, the floating capacity of said holder 26 derived therefrom is controlled by the thumbscrew 28. The prescribed position of said holder 26 is determined by a lock nut 30 engaging said thumbscrew 28. Said holder 26 has a box shape whose top is closed with a cover 31. Numeral 32 is an air cylinder horizontally supported by

nuts

35 and 36 in said holder 26 in its lengthwise direction through

support members

33 and 34. This air cylinder 32 is designed to cause its piston rod 37 to reciprocate by compressed air supply from an air compressor (not shown) and further provided at the upper forward and rear parts with a first and a second

speed control valve

38 and 39 for controlling the advancing and retracting speeds of the piston rod driven by compressed air supplied through two different passages from said air compressor. These

speed control valves

38 and 39 control the amount of air supplied to the cylinder32 by adjusting screws 40 and 41 (FIG. 4). To the forward end of that portion of the piston rod 37 which projects from the holder 26 is attached a connector 44 by

nuts

42 and 43. To said connector 44 is fitted a feed plate 47 by screws 46 through an auxiliary connection plate 45. This feed plate 47 is a thin rectangular plate disposed on the support plate 23 and is intended to receive thereon a shaped work piece M such as a label cut out in a form similar to that of the presser foot I as illustrated in two dot-dash lines in FIG. 4. On said feed plate 47 are mounted a pair of locating members 49 for properly positioning said shaped work piece M, said locating members 49 being fixed to the connection plate by screws 48. To the connector 44 is fixed a guide plate 50 so a to project ahead thereof.

There will now be described by reference to FIGS. 6 to 8 the arrangement associated with the foregoing description. To the guide plate 50 is fitted an actuating rod 51 so as to slide on its surface in the lengthwise direction (to the right and left of said figures). The guide plate 50 is fixed to the connector 44 by a stepped screw 53 inserted through an elongate hole 52 perforated near to the right side of the center of the actuating rod 51. The actuating rod 51 is normally deflected by a spring 55 stretched between a pin 54 projectively disposed substantially at the center of said rod 51 and the stepped screw 53 so as to have its rear end inserted into the actuating frame 26. However, said deflection is restricted by a pin 56 fixed to the guide plate 50 through said elongate hole 52. Numeral 57 is a lock member acting as a stopper, taking a substantially L-shape, one end of which constitutes an engagement portion 58 to register with the rear end of the actuating rod 51 and is rendered rotatable by an operating lever 60 fitted to the end of an actuating shaft 59 crosswise projecting from the holder 26. The lock member 57 is normally urged clockwise of FIG. 2 by a spring 61 wound about the actuating shaft 59. When the feed plate 47 is retracted, the lock member 57 has its engagement portion 58 kept engaged with the rear end of the actuating rod 51, against the action of the spring 55 despite the retraction of the feed plate 47. When the operating lever 60 (FIG. 4) rotates against the action of the spring 55 counterclockwise of FIGS. 6 and 7, the engagement portion 58 of the lock member 57 is disengaged from the actuating rod 51 to retract it bythe action of the spring 55. The forward end of the actuating rod 51 extends downward and has a notch 62 formed at the center of the extended end so as to take a forked shape. There is provided a pin 63 so as to engage said notch 62. The pin 63 is projectively disposed at one end of a stop plate 66 connected to a presser plate 64 by screws 65. Said stop plate 66 and thus presser plate 64 is rotatably fitted by a pivot 67 to the forward end of the guide plate 50 so as to have the pin 63 vertically urged through the notch 62 in response to the advance and retraction of the actuating rod 51 (See FIG. 8). The presser plate 64 is shaped, as illustrated in FIGS. 2 to 8, like a plate whose substantially forward half portion extends downward. This presser plate 64 is so rotated about the pivot 67 as to contact the feed plate 47 through the stop plate 66 and be lifted from said feed plate 47 When the feed plate 47 is retracted, the actuating rod 51 is obstmcted, as shown in FIG. 8, in retraction by the lock member 57, leading to the relative shifting of the feed plate 47 and actuating rod 51. Accordingly, the pin 62 of the presser plate 64 moves downward through the notch 62 to cause the presser plate 64 to rotate about the pivot 67 so as to be lifted above the feed plate 47, that is, a substantially upright position with respect to the actuating rod 51. When, under this condition, the operating lever 60 is rotated against the action of the spring 61, then the lock member 57 is disengaged from the actuating rod 51, which in turn is retracted, as shown in FIGS. 6 and 7, by the action of the spring 55 so as to have its rear end pass over the lock member 57. As the result, the presser plate 64 is rotated to contact the feed plate 47 by engagement between the pin 63 and actuating rod 51.

Numerals 68 to 70 (FIG. 4) denote first to third switches spatially disposed on the inner wall of one of the lengthwise sides of the holder 26. The first switch 68 has its actuator 68F contacted by a switch actuator 71 provided at the other end of the lock member 57, so that when the lock member 57 rotates counterclockwise of FIG. 2, said switch actuator 71 rotates upward to depress the actuator 68? for its closing. The second switch 69 is embedded in the upper part of a metal member 72 extending across the central part of the holder 26, and the third switch 70 is located rearmost, both second and third switches being fitted with actuators 69F and 70P (FIG. 3) respectively, which in turn are each provided with a pulley at the end. Numeral 73 (FIG. 3) represents a guide shaft positioned below the piston rod 37 so as to move jointly therewith. Said guide shaft 73 is rotatably supported at the center by the metal member 72 and integrally fitted at the rear end with a stopper 74 concurrently acting as a switch actuating projection. Said stopper 74 restricts the movement of the guide shaft 73 resulting from the forward travel of the piston rod 37 to a prescribed distance by contacting the metal member 72. As the result, said stopper 74 limits the moving distance of the piston rod 37, that is, the advancing of the feed plate 47 to a prescribed extent. The second and

third switches

69 and 70 are energized when the respective actuators 69F and 7GP contact the polygonal half section of said stopper 74. When depressed by the stopper 74, the actuator 69? of the second switch 69 is urged into an escapement groove formed in the metal member 72. Referring to FIG. 3, numeral 75 represents a support pin for holding the forward end of the actuating frame 26 to prevent its lateral shaking, and numeral 76 denotes the outlet of a cord extending through the base 18 to the controlbox 19.

The presser foot has substantially a pentagon form like the work piece and is provided as shown in FIGS. 9 and near its center with a narrow notch 77 which allows the presser plate 64 (FIG. 6) to pass there through to prevent it from striking against the presser foot When, therefore, a work piece held on the feed plate 47 by the presser plate 64 is placed, as shown in FIG. 12, on the throat plate 5 and the presser foot 10 is brought down to be pressed against said work piece, there does not occur any collision between said presser foot 10 and presser plate 64. Further, the presser foot 10 is provided, as shown in FIG. 9, with a narrow slot 78. When the work piece pressed against the presser foot 10 is sewn as shown in FIG. 12, said sewing starts from said narrow slot 78 and proceeds along the periphery of the presser foot 10, that is, begins, as illustrated in FIG. 11, at point N, follows the periphery S and ends at point 0.

There will now be described by reference to FIGS. 13 and 14 an electric circuit for controlling the operation of a shaped work piece feeding device of the aforementioned arrangement and the associated control electric circuit of the sewing machine.

Numerals

80 and 81 are terminals connected to the electric circuit of the sewing machine. Between the

buses

82 and 83 connected to said

terminals

80 and 81 are provided the following connections. Numeral 84 is a normally open emergency stop switch, which is closed, for example, by hand when the aforesaid work piece feeding device has to be immediately stopped. Said emergency stop switch 84 is connected in such a manner that when it is closed, there is actuated an emergency stop relay 85 to hold itself through a series circuit consisting of the normally open contact 68a of the first switch65 and the normally open contact 85a of said relay 85. Numeral 86 is an exciting coil for returning a first electromagnetic switch valve operating a compressed airpassage disposed in the retracting direction of the piston rod 37. Said coil 86 is energized through the normally closed contact 871), of a first relay 87, which is so connected as to be rendered conducting through the normally closed contact 88b, of the latter described third relay 88 and the normally open contact 89a of a first timer 89. This first timer 89 assures the time required for the presser foot 10 to fall and subsequently for the piston rod 37 to be brought back to its original position, that is, for the feed plate 47 to be retracted from the bed. The contact 89a of said first timer 89 is closed when said timer 89 is energized and opened again upon completion of the counting of the preset time. Numeral b is the normally closed contact of the aforesaid emergency stop relay 85, and disposed between one end of the return exciting coil 86 and that of the first relay 87 both connected to the bus 83. Actuation of the relay 85 resulting from the closing of the emergency stop switch 84 shuts off power supply to other circuits than that associated with the return exciting coil 86. To the first relay 87 is connected a selfholding series circuit consisting of a noamally open contact 68a of the first switch 68, a reverse current preventing diode 90 of the indicated polarity and the normally closed contact 91b, of a second relay 9]. An exciting coil 92 for forwardly working a second electromagnetic switch valve operating a compressed air passage disposed in the advancing direction of the piston rod 37 is so connected as to be energized through the normally open contact 87a of the first relay 87 when it is rendered conducting. Numeral 93 is the exciting coil of an electromagnetic valve (not shown) operating an air passage through which to apply compressed air on to an already sewn work piece so as to remove it from the throat plate before commercing the succeeding cycle of sewing. Said exciting coil 93 is so connected as to be energized through the normally open contact 68a of the first switch 68 when it is closed. Numeral 94a is the normally open contact of a start switch (not shown) disposed in the control box 19 so as to be operated by a push button. This start switch is intended to operate the sewing machine along without using a work piece feeding device. The normally open contact 94a is connected between the bus 82 and a terminal 95 included in the control circuit of the later described sewing ma chine. The normally closed contact 94b of said start switch is connected between the bus 82 and a terminal 96 through the normally closed contact 91b; of the second relay 91. This second relay is connected between the

buses

82 and 83 through the normally open contact 69a of the second switch 69, the normally closed contact 88b of the third relay 88 and a reverse current preventing diode 97 of the indicated polarity, with the later described capacitor 98 connected in parallel. The first timer 89 is rendered conducting through the normally open contact 91a of the second relay 91 when it is closed, as well as through the normally open contact 69a of the second switch 69 when it is closed. There is further provided a self-holding circuit for the second relay 91 connected upon the closing of its normally open contact 91a to the normally closed contact 8811 of the third relay and diode 97. Numeral 99 is a second timer which assures the time required for the clutch mechanism or stop mechanism to be operated when sewing is commenced, and is energized through the normally open contact 70a of the switch 70 when it is actuated as well as through the normally closed contact 87b;, of the first relay 87. This second timer 99 is brought back to its original position when the preset time is fully counted. The contact 99 a of said second timer 99 is connected through a reverse current preventing diode 100 of the indicated. polarity between the bus 82 and the juncture of the diode 97 and second relay 91, thereby energizing both the second relay 91 for a prescribed length of time and the terminal 95 through a reverse current preventing diode 101. The third relay 88 connected in parallel to the secondtimer 99 is energized simultaneously therewith throughits own normally open contact 880 and the normally closed ontact 87b, of the first relay 87 so as to hold itself.

There will now be described the electric circuit of a cycle machine associated with an electric circuit for controlling the operation of the shaped work piece feeding device.

Referring to FIG. 14, numeral 102 represents a transformer which comprises a primary winding 107 with an intermediate tap 106 so as to be energized through a fuse 104 and power supply switch 105 by an A.C. source 103 of, for example, 200 volts and a secondary winding whose turns are chosen to have such a number as to generate A.C. voltage of, for example, 24 volts. Numeral 109 shows a full-wave rectification circuit for converting the A.C. voltage generated in the secondary winding to DC. voltage, to the DC output terminal of said circuit being connected to DC. lines 110 and 1 11, which in turn are connected the

terminals

80 and 81 of the electric circuit of the shaped work piece feeding device. Terminal 95 is connected to the bus 111 through the machine starting relay 112. Between said

D.C. lines

110 and 11 1 is connected an auxiliary relay 114 which is energized through an energy stop switch 113 closed upon the stop of the sewing machine by actuation of the normally closed contact 112b of the start relay 112 and an emergency stop lever (not shown) so as to hold itself later by the closing of its own normally open contact 114a. The terminal 96 is branched into two sections through a clutch switch 115 which is closed interlockingly with the operation of the normally closed contact 114b of said auxiliary relay 114 and the clutch mechanism or stop mechanism and opened when the sewing machine is started through said clutch mechanism. One branched end is connected to the DC. line 111 through a presser foot lifting relay 116, and the other branched end is also connected to said D.C. line 1 1 1 through a circuit consisting of a capacitor 120 and high voltage supply relay 121, said circuit including a parallel arrangement of a resistor 119 and a series circuit of the reverse current preventing diode 117 normally open contact 116a of the presser foot lifting relay 116 discharge resistor 118 normally closed contact 116b of said relay 116. Between the terminal 95 and high voltage supply relay 121 is provided a diode 122 of the indicated polarity. Accordingly, the high voltage supply relay 121 and sewing machine starting relay 1 12 are simultaneously put into operation only when there are actuated the start switch 94 of the electric circuit of the shaped work piece feeding device and the second timer 99.

Numeral 123 is full-wave rectifying circuit for converting the potential divided from A.C. voltage 100 V) to D.C. voltage. Between the

D.C. lines

124 and 125 connected to the DC. output terminal of said full-wave rectifying circuit are disposed a start solenoid 128 energized through the normally open contact 112a of the sewing machine starting relay 112 provided with a parallel arranged diode 126 for short-circuiting a counter electormotive force so as to assure a reliable operation and also a capacitor 127 for extinguishing sparks; and a presser foot lifting solenoid 132 provided with a similar diode 129 to the preceding one for short-circuiting a counter electromotive force and a thyristor 130 for effecting a quick operation and energized through the normally open contact 116a of the presser foot lifting relay 116. According to the sewing machine of this invention, the work piece feeding cam is perfo-tated with a slit so as to carry out the sewing of a work piece from point N through the periphery to point (FIG. 11). Before, therefore, the succeeding cycle of sewing is commenced, it is necessary quickly to shift a contact element connected to the presser plate mechanism for moving the presser foot from the position of the cam groove corresponding to point 0 to that corresponding to point N. This object is attained by a quick feed mechanism. Numeral 133 in FIG. 14 represents a solenoid for actuating said quick feed mechanism. This solenoid 133 is connected in parallel to the start solenoid 128. Numeral 134 denotes a quick feed completion switch which, when the quick feed solenoid 133 is operated, is closed inter-lockingly with, for example, the armature of said solenoid 133. Therefore, after the actuation of the quick feed mechanism by the quick feed solenoid 133, the start solenoid is energized through the quick feed completion switch 134. Referring to the high voltage supply circuit, one end of the branched portion of a circuit extending from the other end of the primary winding 107 is connected to one D.C. line 124 through the normally open contact 121a of the high voltage supply relay 121 including a parallel arrangement of a diode 135 and spark extinguishing capacitor 136. The other end of the aforesaid branched circuit is connected to the other D.C. line 125 through the normally open contact 12111 of the high voltage supply relay 121 including a parallel arrangement of a similar current deflection preventing diode 137 and spark extinguishing capacitor 138. Numeral 139 represents a thyristor for preventing abnormal high voltage from being impressed on the primary winding 107 of the transformer 102.

There will now be described the shaped work piece feeding device of the aforementioned arrangement and the operation of the sewing machine associated therewith. Since, however, the operation of the sewing machine is already well known, description thereof is omitted and reference is only made to those parts of the machine which are particularly related to the shaped work piece feed device of this invention.

1. Power supply FIGS. 13 and 14 illustrate the circuits where there is opened a power supply switch 105, with all the switches brought back to the original position. When, under this condition, the power supply switch is closed, the presser foot lifting relay 116 is energized successively through the normally closed contact 91b of the second relay 91 and the normally closed contact 94b of the start switch both shown in FIG. 13 and the normally closed contact 114b of the auxiliary relay 114 and clutch switch both indicated in FIG. 14. As the result, the normally open contacts 116a, and 11611 of the relay 116 are closed and the normally closed contact 116b thereof is opened. Thus the high voltage supply relay 121 is energized through the capacitor only for a short length of time required to charge it. Upon the closing of the normally open contacts 121a and 121a the presser foot lifting solenoid 132 is energized by high voltage current, for example, 200 volts obtained by rectifying alternating current supplied by the A.C. source 103, thereby lifting the presser foot 10 through the action of a mechanism for vertically moving said presser foot 10. Later when the capacitor 120 is fully charged, the high voltage supply relay 121 is brought back to its original position. As the result, the presser foot lifting solenoid 132 energized up to this point with high voltage current is now actuated by low voltage current obtained from the full-wave rectifying circuit 123, keeping the presser'foot 10 in a lifted position. When, under this condition, the return exciting coil 86 is energized through the normally closed contact 87b, of the first relay 87 of FIG. 13, then the piston rod 37 is inserted into the cylinder 32.

2. Operation of the shaped work piece feeding device and the associated operation of the sewing machine Under the above-mentioned condition, there is properly placed by the locating member 49 a shaped work piece M, for example, a label similar to the presser foot 10, as illustrated in two dot-dash lines in FIG. 4, on the upper surface of the feed plate 47 of the work piece feeding device. At this time, the presser plate 64 is lifted above the feed plate 47, that is, is set upright substantially at right angles to the actuating rod 51. This position is maintained while the actuating rod 51 has its rear end contacted by the engagement portion 58 of the lock member 57 and advances against the action of the spring 55. When, after placement of the work piece M on the feed plate 47,'the actuating lever 60 is rotated counterclockwise of FIG. 2, and the actuating pin 59 is operated in the same direction against the action of the spring 61 to rotate the lock member 57, then the actuating rod 51 has its rear end disengaged from the engagement portion 58 of the lock member 57, and is retracted by the action of the spring 55 along the guide plate 50. Upon said retraction, the presser plate 64 connected to the actuating rod 51 through engagement between the forward end of said rod 51 and pin 63 rotates about the pivot 67 to contact the feed plate 47, thereby causing the shaped work piece M to be pressed against the upper surface of the feed plate 47 by the presser plate 64. At this time, the lock member 57 rotates and the switch actuator 71 thereof pushes up the actuator 68F of the first switch 68 to close it. As the result, the first relay 87 of FIG. 13 is rendered conducting through the normally open contact 68a of the first switch 68, diode 90, and the normally closed contact 91b, of the second relay 9] in turn, and later holds itself through a circuit including its own normally open contact 87a and the norally closed contact 91b, of said second relay 91. At the same time, the exciting coil 93 is energized through the normally open contact 680 of the first switch 68, causing air to be momentarily ap plied to the upper surface of the machine bed by the opening of the corresponding electromagnetic valve so asto remove from the bed surface the work piece already sewn during the preceding cycle. Later a fresh work piece is placed on the surface of the machine bed. When, under this condition, the normally open contact 87a of the first relay 87 is closed to energize the exciting coil 92 of the electromagnetic valve so as to switch it, the cylinder 32 is supplied with compressed air through said valve to move the piston rod 37 in the forward direction. Accordingly, the feed rate 47 is urged from its waiting position on the support plate, with the work piece M held by the presser plate 64, toward the underside of the lifted presser foot 10. Immediately after the piston rod 37 commences its forward travel, the actuator 70? is urged upward by the stopper 74 of the guide shaft 73 moving jointly with said travel to actuate the third switch 70, thereby closing its contact 70a. Since, at this time, the first relay 87 still continues to be operated with its normally closed contact 87b left open, there is no possibility of the third relay 88 and second timer 99 being energized.

When the piston rod 37 advances until the stopper 74 of the guide shaft 73 is contacted by the metal member 72, that is, the feed plate 47 is brought to its operating position right below the lifted presser foot 10 then the second switch 69 has its actuator 69F depressed by the stopper 74 to close its contact 69a, causing the second relay 91 to be energized through said contact 69a, the normally closed contact 88b of the third relay 88 and diode 97 in turn and hold itself by a circuit consisting of its own normally open contact 91a, said normally closed contact 88b and diode 97. When the normally open contact 91a of the second relay 91 is closed, the first timer 89 is energized therethrough to commence the counting of the preset time with its contact 89a closed.

When the normally closed contact 91b of the second relay 91 is opened, the first relay 87 connected thereto id deenergized. When, instead, the contact 88a is close due to the actuation of the first timer 89, the first relay 87 begins to be energized through said contact 89a and the normally closed contact 88!), of the third relay 88. Said energization of the first relay 87 lasts until the present time period of the first timer elapses and ceases when its contact 89a is placed on that poart of the machine bed which is disposed right below the presser foot and the second switch 69 is energized with its normally open contact 69a closed, then the first and

second relays

87 and 91 are actuated at the same time. The resultant opening of the normally closed contact 87b of the first relay 87 ceases the energization of the return exciting coil 82 only for the preset time of the timer 89, thereby temporarily obstructing the retraction of the piston rod 37. While said piston rod 37 stands at rest, the presser foot 10 is let fall by the opening of the normally closed contact 9lb of the second relay 91. Said opening obstructs the energization of the presser foot lifting relay 116 through the normally closed contact 11411 of the auxiliary relay 114 and clutch switch 115. While the normally open contact 11611 of the presser foot lifting relay 116 remains opened dueto its return to the original position, the presser foot lifting solenoid 132 is deenergized, causing the presser foot 10 to be brought down by the force of the spring of the presser foot actuating mechanism so as to be pressed against a shaped work piece M placed on the machine bed with the feed plate 47 interposed therebetween. Almost as soon as the descending presser foot 10 is pressed against the shaped work piece M on the feed plate 47, the first timer 89 completes the counting of its preset time to have its contact 89a opened. Accordingly, the first relay 87 is deenergized to return to its original position and the opening of its normally closed contact 87b, leads to the energization of the return exciting coil 86, causing the piston rod 37 to be retracted into the cylinder 32. As a result, the feed plate 47 returns to its waiting position on the support plate 23 with said retraction of the piston rod 37. At this time, the shaped work piece M still remains pressed against the surface of the machine bed by the presser foot regardless of the movement of the feed plate 47, which alone is released from depression by the presser foot to return to its original position.

During the return of said feed plate 47 (immediately before the end of said return), the actuating rod 51 has its rear end introduced into the holder 26 to be pressed against the engagement portion 518 of the lock member 57 brought back to its original position by the action of the spring 61, and consequently is prevented from being urged with the movement of the feed plate 47 or piston rod 37. This gives rise to different states between said actuating rod 51 and a member travelling therewith, for example, the guide plate 50. Namely, the actuating rod 51 forwardly urges the stopped guide plate 50 against the action of the spring 55. This operation causes the presser plate 64 engaging the actuating rod 51 by the pin 63 to be set upright relative to said actuating rod 51, that is, to be lifted above the feed plate 47. Thus the presser plate 64 is automatically brought back during its return to an inoperative position by the action of the actuating rod 51 and lock member 57. Later when the piston rod 37 is fully retracted and the feed plate 47 is brought back to its waiting position on the support plate 23, then the stopper 74 of the guide shaft 73 which moved with the piston rod 37 actuates the third switch 70 through engagement with its actuator 70P, thereby closing the normally open contact 70a of said third switch 70. Upon the closing of the normally open contact 70a, the third relay 88 is first energized to hold itself through its own normally open contact 88a and the normally closed contact 87b of the first relay 87. At this time, the second relay 91 ceases to be energized through its selfholding circuit by the opening of the normally closed contact 88b of the third relay 88. On the other hand, the second timer 99 is operated simultaneously with the actuation of the third relay 88 through the same circuit to complete the counting its preset time, and the second relay 91 is energized upon the closing of the contact 99a of the time 99 through said contact 99a and diode 100 only for the preset time of the timer99. Accordingly, the presser foot lifting relay 116 remains deenergized to to prevent the presser foot from being lifted.

Preparation is made for the succeeding cycle of sewing by actuating, as described above, the second relay 91 only for the preset time of the second timer 99 and operating the clutch mechanism within said preset time with the presser foot kept in a lower position. Upon the closing of the contact 99 1 of the second timer 99, the start relay 112 of the sewing machine is energized simultaneously with the actuation of the second relay 91 through the contact 99a of the second timer 99, diode 101 and terminal 95, thereby closing the normally open contact 1 12a of said start relay 112. Thus the high voltage supply relay 121 is energized through the same circuit and diode 122 to have its normally open contacts 121a and l21a closed. Upon the closing of the quick feed completion switch 134 due to the action of the quick feed solenoid 133, the start solenoid 128 is energized as in the case of the presser foot lifting solenoid 132, by high voltage current, for example, DC. voltage of 200 V converted from alternating current supplied by the A.C. source 103. A clutch mechanism (not shown) causes a belt (not shown) to rotate the drive shaft, thereby enabling the sewing machine to commence sewing. Later when the second timer 99 completes the counting of its preset time to have its contact 99a opened, then the second relay 91 is deenergized to return to its original position. Though, at this time, the normally closed contact 91b of said second relay 91 still remains closed, yet the pressor foot lifting relay 116 is not energized, thus preventing the presser foot 10 from being lifted during sewing. Of course, the third relay 88 is kept in the aforesaid selfholding state during sewing.

As mentioned above, the shaped work piece is sewn on to the body of a suit by vertically reciprocating a needle along the periphery of the presser foot, that is,

moving said work piece over the bed surface together with the presser foot travelling lengthwise and crosswise by the action of the feed mechanism perpendicularly to the direction in which the needle is made to reciprocate, thereby completing one cycle of sewing. Upon said completion, the belt is transferred from the operative blocks to the floating blocks by the returning action of the clutch mechanism which releases the action of the stop lever operated up to this point. Thus the clutch switch is brought back to its original closed position, causing the presser foot lifting relay 116 to be energized through the normally closed contact 9112 of the second relay 91, the normally closed contact 9412 of the start switch, terminal 96, the normally closed contact 114b of the auxiliary relay 114 and clutch switch 115. As the result, the high voltage supply relay 121 is temporarily energized to lift the presser foot 10, thus rendering the sewing machine ready for the succeeding cycle of sewing. Even under this condition, the high voltage supply relay 121 returns to its original position by the aforesaid action, so that the maintenance of the presser foot 10 at its lifted position is effected by energizing the presser foot lifting solenoid 132 with low voltage current.

When the operator of the machine places by hand a fresh shaped work piece M on the feed plate 47 for the succeeding cycle of sewing to be pressed thereagainst by the presser plate 64, the first switch 68 is operated by the action of the switch actuator 58 of the lock member 57 to have its normally open contact 68a closed. Accordingly, the exciting coil 93 is energized to supply air in a manner to blow off the already sewn work piece from the bed surface. The first relay 87 is energized to bring the relay 88 back to its original position, and the advance exciting coil 92 is also actuated to cause the feed plate 47 to be urged below the lifted presser foot by the forward movement of the piston rod 37. Repetition of the aforementioned operation automatically and successively supplies a label or other shaped work pieces M to the bed surface.

Where there is to be performed such type of sewing as can be fully attained simply by an ordinary sewing machine without using the work piece feeding device of this invention, the presser foot is lifted by throwing a power supply source, and the start switch of FIG. 13 is operated to have its normally open contact 94a closed. Then the start relay 1 l2 and high voltage supply relay- 121 are energized to let fall the presser foot 10. Thus the sewing machine is operated through the aforementioned steps. Since the quick feed solenoid 133 is energized before the start solenoid 128, the quick feed mechanism is actuated before the machine commences sewing so as to instantly return the presser .foot from the position where the needle completed sewing to that where it is ready to start sewing. Where the emergency stop switch 84 is closed during the operation of the shaped work piece feeding device, the emergency stop relay is energized to have its normally open contact 85a closed and holds itself through a circuit consisting of its own contact 850 and the normally closed contact 68b of the first switch 68, deenergizing all other circuits than that associated with the return exciting coil 86. Accordingly, the feed plate 47 is brought back to its original position immediately at the return of the piston rod 37. The capacitor 98 of the electric circuit of FIG. 13 is intended to prevent the second relay 91 from being energized through a circuit including the norfications in so far as the object of the invention is not changed. For example, the feed plate 47 may be driven not only by the aforementioned air cylinder, but by other mens such as oil pressure, motor or manual operation.

What is claimed is:

1. A device of the character described (17) having a forward end feed plate (47) comprising:

a. a base (18) holding a support rod (21) vertically adjustable in said base;

b. elongated flat plate support means (20,33) with said feed plate at the forward end thereof and pivot means (25) at the other end, with resilient means (29) intermediate said ends disposed for applying a resilient force substantially normal to said flat plate support means (20, 23);

c. an elongated holder (26) pivoted at one end by said pivot means (25) and kept in suspension by said resilient means (29);

d. an air cylinder (32) in said holder including piston means (37) disposed for longitudinal movement therein with a connector (44) at the forward end thereof, said feed plate (47) being attached to said connector (44);and,

e. locating member (49) on said feed plate (47) for positioning a workpiece thereon.

2. In a sewing machine with a work plate, afeeding device for feeding a work piece to said work plate comprising:

a. a support disposed adjacent to said machine;

b. a vertically movable holder mounted on said support;

0. first spring means provided between said holder and support so as to keep said holder in a floating condition;

(1. a guide bar supported on said holder so as to move horizontally with one of its ends projecting from said holder;

e. a feed plate secured to the projected end of said guide bar to receive a work piece thereon;

f. a locating member mounted on said feed plate so as to properly place the work piece thereon;

g. actuating means supported on said holder so as to move said guide bar with said feed plate in the floating condition to a retracted position in which to place the work piece on said feed plate and to an advanced position in which to feed the work piece on the throat plate;

h. a presser plate pivotally mounted on said guide bar so as to press said work piece against said feed plate;

i. an actuating bar supported on said guide bar for relative movement thereto with one of its ends movably connected to said presser plate;

j. second spring means provided between said actuatso as to stop said actuating bar by engagement with its other end against the action of said second spring means regardless of the retraction of said guide bar, said stopper being disengaged from said actuating bar when the manually operable bar actuates said control means against the action of the third spring means, thereby causing the actuating bar to bring down said presser plate by the second spring means so as to press the work piece against the feed plate.

3. In a sewing machine with a work plate, a feeding device for feeding a work piece to said work plate in cluding a frame provided with a bed and having a reciprocable needle supported on the frame, a presser foot horizontally movable on said work plate across the reciprocating direction of said needle so as to carry the work piece along a predetermined path, said presser foot being adapted to be brought down on to said work 7 plate and lifted therefrom which further comprises:

a. a support disposed adjacent to said sewing machine;

b. a feed plate mounted on said support for limited movement vertically and horizontally and disposed to place said work piece onto said throat plate;

c. resilient means disposed between said feed plate and support so as to keep said feed plate in a floating condition; and,

d. actuating means for moving said feed plate in the floating conditions to a retracted position in which to feed the work piece thereon and to an advanced position in which to feed the work piece under the lifted presser foot, said presser foot being brought down to press the work piece against said work plate when said feed plate is brought to said advanced position and said feed plate then being brought back to said retracted position leaving said work piece under the lowered presser foot.

4. A device according to claim 3, wherein said support includes a supporting plate disposed adjacent to the end of said bed with the upper surface made flush with said work piece supporting plane of the bed.

5. A work piece feeding device according to claim 3 wherein said feed plate includes a presser plate movably mounted thereon so as to press said work piece against said feed plate, said presser foot being perforated with a slot which, when said feed plate is advanced, permits said presser plate to fall therethrough with said work piece pressed against said feed plate by said presser plate.

Patent No. ,7 7,422 Dat d March19, 1974 inventor KATSUAKI SAKAWA It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

On the co ver sheet [73] Assignee, "Brother Kogy Kabushiki Kaisha," should read Brother Kogyo Kabushiki Kaisha,

Signed and sealed this 13th day of Augnst' 1974..

(SEAL) Attestz v I V McCOY M GIBSON; JR, (1. MARSHALL DANN' Attes'ting Officer Commissioner of Patents FORM "M050 USCOMM-DC scan-Pu lLS. GOVIINKINT I'IPITIIG OFFICE 2 H" O'JQC-SM.

Claims

1. A device of the character described (17) having a forward end feed plate (47) comprising: a. a base (18) holding a support rod (21) vertically adjustable in said base; b. elongated flat plate support means (20,33) with said feed plate at the forward end thereof and pivot means (25) at the other end, with resilient means (29) intermediate said ends disposed for applying a resilient force substantially normal to said flat plate support means (20, 23); c. an elongated holder (26) pivoted at one end by said pivot means (25) and kept in suspension by said resilient means (29); d. an air cylinder (32) in said holder including piston means (37) disposed for longitudinal movement therein with a connector (44) at the forward end thereof, said feed plate (47) being attached to said connector (44);and, e. locating member (49) on said feed plate (47) for positioning a workpiece thereon.

2. In a sewing machine with a work plate, a feeding device for feeding a work piece to said work plate comprising: a. a support disposed adjacent to said machine; b. a vertically movable holder mounted on said support; c. first spring means provided between said holder and support so as to keep said holder in a floating condition; d. a guide bar supported on said holder so as to move horizontally with one of its ends projecting from said holder; e. a feed plate secured to the projected end of said guide bar to receive a work piece thereon; f. a locating member mounted on said feed plate so as to properly place the work piece thereon; g. actuating means supported on said holder so as to move said guide bar with said feed plate in the floating condition to a retracted position in which to place the work piece on said feed plate and to an advanced position in which to feed the work piece on the throat plate; h. a presser plate pivotally mounted on said guide bar so as to press said work piece against said feed plate; i. an actuating bar supported on said guide bar for relative movement thereto with one of its ends movably connected to said presser plate; j. second spring means provided between said actuating bar and guide bar so as to normally set said presser plate in said pressing position; k. control means mounted on said holder so as to operate said actuating means, thereby bringing said bar to the advanced position; l. a manually operable lever mounted on said holder and provided with an actuating member for operating said control means; m. third spring means disposed between said manually operable lever and holder so as to normally prevent said actuating member from operating said control means; and, n. a stopper secured to said manually operable lever so as to stop said actuating bar by engagement with its other end against the action of said second spring means regardless of the retractIon of said guide bar, said stopper being disengaged from said actuating bar when the manually operable bar actuates said control means against the action of the third spring means, thereby causing the actuating bar to bring down said presser plate by the second spring means so as to press the work piece against the feed plate.

3. In a sewing machine with a work plate, a feeding device for feeding a work piece to said work plate including a frame provided with a bed and having a reciprocable needle supported on the frame, a presser foot horizontally movable on said work plate across the reciprocating direction of said needle so as to carry the work piece along a pre-determined path, said presser foot being adapted to be brought down on to said work plate and lifted therefrom which further comprises: a. a support disposed adjacent to said sewing machine; b. a feed plate mounted on said support for limited movement vertically and horizontally and disposed to place said work piece onto said throat plate; c. resilient means disposed between said feed plate and support so as to keep said feed plate in a floating condition; and, d. actuating means for moving said feed plate in the floating conditions to a retracted position in which to feed the work piece thereon and to an advanced position in which to feed the work piece under the lifted presser foot, said presser foot being brought down to press the work piece against said work plate when said feed plate is brought to said advanced position and said feed plate then being brought back to said retracted position leaving said work piece under the lowered presser foot.