close

Вход

Забыли?

вход по аккаунту

?

Патент USA US3024757

код для вставки
March 13, 1962
K_ w
3,024,750
AUTOMATIC LOCKING STITCH CONTROL SYSTEM FOR
SEWING AND THE LIKE MACHINES
Filed Aug. 28, 1958
2 Sheets-Sheet 1
I
\
INVENTOR.
m\ m wm/z
BY
‘WW/h
March 13, 1962
K. WINZ
AUTOMATIC LOCKING STITCH CONTROL SYSTEM FOR
SEWING AND THE LIKE MACHINES
Filed Aug. 28, 1958
3,024,750
2 Sheets-Sheet 2
ATTO R N EY
tates Patent O?iice
1
3,024,750
Patented Mar. 13, 1962
2
and being returned to rest or inoperative position upon
3,024,750
completion of the locking stitch operation, to be ready
AUTOMATIC LOCKING STITCH CONTROL SYS
TEM FOR SEWING AND THE LIKE MACHINES
for the initiation of a renewed operation in connection
Karl Winz, Kaiserslautern, Pfalz, Germany, assignor to
G. M. Pfaff A.G., Kaiserslautern, Pfalz, Germany, a
corporation of Germany
Filed Aug. 28, 1958, Ser. No. 757,834
Claims priority, application Germany Aug. 31, 1957
10 Claims. (Cl. 112-203)
said machine.
The invention, as to its ancillary objects as well as
novel aspects, will be better understood from the follow
ing detailed description, taken in reference to the accom
The present invention relates ‘to an electric control sys
with either the same or a different seam being sewn by
panying drawing forming part of this speci?cation and
10 wherein:
FIG. 1 is a perspective view of a sewing machine em
tem for sewing and the like machines of the type equipped
with an electrically operable stitch control device, to
bodying control means according to the invention;
reversing device being normally urged, by a spring or
the like, to a position for forward stitching may be oper
ferent views of the drawings.
With the foregoing objects in view, the invention in
ated in a known manner by a solenoid having a control
' volves generally the provision of an electric control sys
FIG. 2 is a partial view of the presser foot and work
change from ‘forward to reverse stitching, vand vice versa.
and illustrating the sewing of the locking or backtacking
More particularly, the invention is concerned with the 15 stitches; and
production of a pre-determined number of forward and
FIG. 3 is a circuit diagram of a complete electric con
reverse locking or backtacking stitches at a desired posi
trol system for the automatic sewing of backtacking or
tion, including the starting and end position, of a seam
locking stitches as shown by FIG. 2.
being sewn by said machine. The backtacker or stitch
Like reference characters denote like parts in the dif
magnet or an equivalent electrically operable actuating
means, to change to reverse stitching during the energiza
tion thereof by an electric control current.
In producing locking or backtacking stitches of this
type, in accordance with conventional methods and prac
tern or device for sewing machines of the type described
and adapted to automatically effect, at normal operating
25 speed of the machine, a predetermined number of for
ward and reverse locking stitches at a desired point, in
cluding the starting and end points, of a seam being sewn
by said machine, the number of locking stitches being
point, the operator had to slow down the machine, such
pre-selectable by the operator, to suit existing sewing con
‘as by the operation of a knee-lever or equivalent control 30 ditions and requirements.
member, in order to be able ?rst to count a desired num
With these aims in view, the invention contemplates
ber of forward looking stitches, to subsequently count the
generally the utilization of a synchronous pulse generator
tice, such as to lock a seam at its beginning or starting
same number ‘of reverse locking stitches upon operation
driven from the drive shaft or an equivalent operative
of the machine from forward to reverse stitching and,
organ of a sewing machine, to produce a series of electric
?nally, to return to forward stitching for the sewing and 35 counting pulses, each pulse preferably representing a single
completion of the seam. The same applies to the pro—
stitching operation and being applied to a pulse counter,
duction of a group of locking stitches at any other point,
for example a conventional stepping switch or relay. The
such as at the end of the seam being sewn by the machine.
stepping switch may comprise a movable contact cooperat
This method as used in the past is both time consum
ing with a plurality of stationary contacts progressively en
ing and dependent to a large extent upon the personal fac 40 gaged by said movable contacts in synchronism with the
tor, whereby to require skilled labor, aside from other
succession of stitch counting pulses. The stationary con~
shortcomings and drawbacks as will be obvious.
tacts of the stepping switch are, in turn, connected, pref
Accordingly, an important object of the present in
erably through a relay or the like, with the electrical con
vention is the provision of an electric control system for
trol circuit of the backtacker or stitch reversing device,
sewing machines equipped with electrically operable stitch 45 such as through an electromagnetic solenoid control de
control means to change from forward to reverse stitch
vice, by way of a multiple-element pre~selector switch, in
ing, and vice verse, by which the above and related dif
such a manner as to provide a plurality of branch circuits
?culties are substantially overcome or minimized.
and to energize said stitch reversing device, to change
A more speci?c object of the invention is the provision
of a control system of the type mentioned, whereby a pre
from forward to reverse stitching upon the occurrence of
50 a pre-selected number of counting pulses and completion
determined number of forward and reverse locking
of a corresponding number of forward locking stitches.
stitches may be produced positively and securely at a
Furthermore, said selector switch elements may be
desired point of a seam being sewn by a sewing machine.
mutually interconnected, to cause an equal number of
Another object of the invention is the provision of a
reverse locking stitches superimposed upon said forward
locking stitch control system of this type by means of 55 locking stitches and to de-energize said stitch reversing
which a desired number of locking stitches may be pro
device and to return the same to the forward stitiching
duced at normal operating speed of a sewing machine
direction for the normal sewing of a seam by the ma
economically and expeditiously, as Well as substantially
chine. Additional means may be provided to return the
free from the effects of the personal factor and other
pulse counter or step-ping switch to its zero or starting
defects inherent in the previously known methods.
60 position upon reaching the ?nal counting pulse or contact
Yet another object of the invention is the provision of
of the stepping switch and, furthermore, the pulse counter
circuit may be normally interrupted and connected to
a locking stitch control system of the above type, whereby
start counting of the stitches or pulses at the desired in
the number of automatically produced locking stitches
stant or position of the seam, where the sewing of lock
may be pre-selected, to suit any existing operating or sew
ing conditions and requirements.
65 ing or tacking stitches is desired. Thus, where the look
ing stitches are desired at the start of ‘a scam, the count
A further object of the invention is the provision of a
ing circuit may be closed at the time of starting of the
locking stitch control system for sewing machines, to auto
stitching opentaion, to initiate the counting of the forward
matically e?fect a selectable number of forward and re
verse locking stitches at a desired point of a seam being
locking stitches. Alternatively, the counting pulses may
be started at any other position of the seam, such as by
sewn by said machine, said system being in operative 70 means of a separate stitch counter or synchronous timing
condition during the actual lock stitching operation only
device, to initiate the sewing of a pre-determined group
3,024,750
4
3
of locking stitches at a desired point, including the begin
ing and to return to forward stitching after completion
ning and end of a seam being sewn by the machine.
Referring more particularly to FIG. 1 of the drawings,
the sewing machine shown, being of standard and conven
tional construction, comprises a stitch direction control
or backtacker 11’ normally urged to a position for for
ward stitching by means of a return spring or the like
and operable to a reverse stitching position by the electro
of an equal number of reverse locking stitches, as will
become further apparent from the following.
There is further shown in the drawing a monitor or
auxiliary switch 12 connected in the pulse counter circuit
of the stepping switch magnet D and controlling the
operativeness of said counter, a control switch 22 to re
turn the system to inoperative position upon completion
of a sewing cycle, further details of the circuit and system
being in part described and in part becoming apparent
magnet or solenoid 9 through a chain 9’ or the like
coupling member. The machine furthermore comprises
a stitch counter in the form of a cam 10’ mounted upon
the arm shaft 12’ and controlling a circuit interrupter
or make and break device 10, to produce a counting pulse
for each operating cycle or stitch being sewn by the ma
15
chine, in a manner readily understood.
FIG. 2 illustrates the ordinary way of producing the
backtacking or locking stitches in a pair of work pieces
M1 and M2 ‘at the starting point of the seam by ?rst sew
ing a limited number, say three, forward locking stitches,
from the following description of the operation of the
invention.
When the sewing machine is driven by the motor 2,
the interrupter 10 mounted upon the driven shaft of the
machine closes once during each revolution or during
each stitching operation, the exciting circuit of the magnet
coil of the stitch counter D through a circuit being traced
as follows:
(1) Terminal 7 of recti?er 6, monitor switch 12, termi
as indicated by the arrow a in the drawing, placing the 20 nal 13, interrupter contact 10, contact In of relay A,
terminal 14, step relay coil D, terminal 15 and terminal
stitch control in reverse and sewing the same number of
8 of recti?er 6.
reverse locking stitches, as indicated by the arrow b, and
As a result the contact arms 3d, 4d and 5d initially
?nally returning to forward stitching, to continue the
engaging the contacts 3d0, 4110 and Sdt) of the respective
Referring to the control circuit, FIG. 3, the reference 25 banks 3d0-3d10, 4d0~4d10 and Sdtl-Sdlt), are advanced
scam s, as indicated by the arrow 0.
characters T R S represent a convention three-phase
power supply system including a neutral conductor N
which serves to supply the three-phase driving motor 2 of
the sewing machine, such as a squirrel cage or induction
motor, connectable through a main operating switch 1, a 30
pilot lamp 3 being providing to indicate the operative
from one to the next higher contact by the successive
counting pulses controlling the stepping switch.
As an example, let it be assumed that it is desired to
produce three locking stitches at the beginning of a seam.
For this purpose, the operator closes or presses the con
tact or group 3c of the pre-selector switch C.
As a consequence, after the pulse generator 10‘ has
‘closed three times the exciting circuit (I) of the stitch
or running condition of the motor. Further connected
to the neutral conductor N and one of the phases of the
counter or stepping switch magnet D, the contact arms
power network is a ?rst bridge recti?er 4, having output
terminals 16 and 17 to supply D.C. operating current for 35 3d, 4d and 5d engage the contacts 3d3, 4:13 and 5d3,
respectively, whereby a circuit will be closed by way of
the stitch direction control device or solenoid 9, and the
the contact 3d3 including the starting relay winding B
primary winding of a step-down transformer 5 energizing
and being traced as follows:
a further recti?er 6 having output terminals 7 and 8 to
(II) Terminal 7 of recti?er 6, monitor switch 12,
supply D.C. operating current for the stitch control sys
tem of the invention. The recti?ers 4 and 6 may be of 40 terminal 13, winding of the starting relay B, contact 30,
contact 3d3, contact arm 3d, terminal 15 and terminal 8
any suitable type, such as dry or contact recti?ers, PN
of the recti?er 6.
germanium or silicon junction recti?ers or the like.
As a result, the starting relay B closes its contact 2b,
whereby to energize the solenoid 9 of the stitch reversing
The locking stitch control system, shown by way of
example, comprises essentially (l) a pulse generator
shown in the form of an interrupter switch 10 operated 45 magnet through a circuit traced as follows:
(III) Terminal 16 of recti?er 4, contact 2b, reversing
by a cam 10’ driven from the drive shaft (see FIG. 1) or
magnet winding 9, and terminal 17 of recti?er 4.
an equivalent operative organ of the sewing machine, to
Connected in parallel to the contact 217 of the starting
produce a series of electric counting current pulses, pref
relay is a spark quenching circuit 18 comprising in a
erably one for each revolution or stitching operation of
the machine, (2) a stopping relay A having a contact 1a, 50 known manner an electrical capacitor in series with a
high-ohmic resistor. Energization of the reversing
to interrupt the counting pulses upon completion of a
magnet 9 in a known manner causes a reversal of the
locking stitch operation, whereby to normally maintain
stitching direction or change from forward to reverse
the control circuit in the non-operative or rest position
stitching, as pointed out hereinahove.
and to establish its operative condition only just prior to
Since the sewing machine continues to operate the
the instant when a locking stitch operation is desired at 55
circuit (1) will be closed once by each of the next follow
a pre-determined point of a seam being sewn by the ma
ing three counting pulses produced by the interrupter 10,
chine, (3) a starting relay B having a contact 2b, to oper
whereby to energize the stitch counting winding D and
ate the stitch direction control device from forward to re
to advance the contact arms 30?, 4d and 5d to the con
verse stitching upon the occurrence of a pre-selected num
ber of forward locking stitches, (4) a multiple pre-selec
60 tacts 3d6, 4d6 and 5:16, respectively.
tor switch C for selecting a desired number of locking
stitches having switch elements or groups of switch ele
ments or units 10 to 5c, in the example illustrated in the
As soon as the
contact arm 3d engages the contact 3d6, the exciting cir
cuit (II) for the starting relay B will be interrupted,
whereby to open the contact 2b and to interrupt the ex
citing circuit (HI) of the reversing magnet 9. As a result
drawing, and (5) a locking stitch counter, for example,
in the form of a stepping switch or relay having a control 65 the feed direction is returned to forward stitching for the
normal sewing of a seam by the machine. In this man
magnet D energized by said counting pulses and having
ner, a series of three forward and three backtacking
movable contact arms 3d, 4d and 5d arranged for syn
stitches is automatically sewn by the machine, in the man
chronous operation, as indicated by the dot-dash line 11,
ner shown by FIG. 2.
and cooperating stationary contacts 3d0-3d10, 4d0-4d10
After the ‘machine has sewn, in the cxempli?cation
and 5d0-5d10, respectively. The stepping relay or stitch 70
illustrated, a total of ten stitches, that is after the con
counter may be constructed in the form of a conventional
tact arms 3d, 4d and 5d have reached the stationary con
rotary switch, well known to those skilled in the art, and
serves to operate the stitch reversing device through relay
B upon the occurrence of a selected number of forward
locking stitches, to change from forward to reverse stitch 75
tacts 3d10, 4d10 and 5(110, the exciting circuit for the
stopping relay A Will be closed as follows:
(IV) Terminal 7 of recti?er 6, terminal 23, terminal
3,024,750
5
6
19, stopping relay winding A, resistor 20, contact 5d10,
by said machine, stepping switch means controlled by said
contact arm 50!, terminal 21, terminal 15, and terminal 8
pulses having movable contact means and a plurality of
stationary contacts cooperating therewith, a locking stitch
controller comprising a plurality of individual selector
switches having progressively increasing numbers of multi
ple contacts corresponding to varying numbers of locking
stitches to be sewn, and multiple circuit connections inter
connecting said selector switch contacts with each other,
with said stepping switch contacts and said circuit,
10 whereby to close said circuit and to operate said stitch
of recti?er 6.
,
Excitation of the stopping relay A causes its contact 1a
to be opened, whereby to interrupt the circuit (I) of the
stitch counter D until the ?nal stoppage of the sewing
machine. As soon as the machine has been stopped, an
auxiliary switch 22 will be closed, for instance by the
lifting of the presser or clamp foot or an equivalent oper
ative organ of the machine, thereby brie?y closing a re
turn circuit of the stitch counter being traced as ‘follows:
(V) Terminal 7 of recti?er 6, terminal 23, contact
41110, contact arm 4d, switch 22, terminal 14, magnet
coil D, terminal 15 and terminal 8 of recti?er '6.
control from forward to reverse stitching upon the sewing
of varying numbers of forward locking stitches and to
open said circuit and to return said ‘stitch control to for
ward stitching upon the subsequent sewing of equal num
As a consequence, the contact arms 3d, 4d and 5d 15 bers of reverse locking stitches by said machine by opera
are returned to the starting contacts 4d0, 4d0 and ‘5d0,
while a pilot lamp 24 ‘will be lit ‘by way of the contact
tion of the respective selector switch of said controller.
2. The combination with a sewing machine compris
5d0, indicating the readiness of the machine for a re
ing an electrically actuatable stitch control having an ex
newed locking stitch operation. The circuit for the pilot
citing circuit, to change from forward to reverse stitching
during closing of said circuit; of a control system for
automatically producing a selectable number of forward
lamp 24 is traced as follows:
(VI) Terminal 7 of recti?er 6, terminal 23, terminal
19, terminal 25, pilot lamp 24, resistor 26, contact 5:10,
and reverse locking stitches at a predetermined point of a
contact arm 5d, terminal 21, terminal 15, and terminal 8
of the recti?er 6.
seam being sewn by said machine comprising pulse gen
erating means controlled by said machine, to produce ‘a
As a result, the exciting circuit (IV) of the stopping 25 series of electric pulses one for each stitch being sewn by
relay and the return circuit (V) of the stitch counter
said machine, means to initiate said pulses at the prede
D will be interrupted.
termined point of said seam, stepping switch means hav
If it is ‘desired to produce a different number of locking
ing a control magnet with means to energize the same by
stitches, for example a maximum of ?ve stitches in the
said pulses, a movable contact controlled by said magnet
example illustrated, it is necessary to close or depress the 30 and a plurality of stationary contacts cooperating there
contact group So of the selector switch, whereby to effect
with to progressively advance said movable contact from
operation of the starting relay B after ?ve counting pulses
one to the next stationary contact by said counting pulses,
or upon engagement by the contact arms 3a’, 4a’ and 5d of
a locking stitch controller comprising a plurality of in
contacts '3a'5, M5 and 5d5, respectively, again resulting in
dividual selector switches having progressively increasing
the excitation of the reversing magnet 9. The latter be 35 numbers of multiple contacts corresponding to varying
comes de-energized upon the arms 3d, 4d and 5d leaving
numbers of locking stitches to be sewn, and multiple
the contacts 3d9, M9 and 5119, respectively, that is, after
circuit connections interconnecting said selector switch
the sewing of ?ve reverse locking stitches and return of
contacts with each other, with said stepping switch con
tacts and with said circuit, whereby to ?rst close said
40 circuit and to operate said stitch control from forward to
tially the same manner as described hereinbefore.
The sewing of the same selected number of forward
reverse stitching upon the sewing of varying numbers of
and reverse locking stitches is enabled by the arithmeti
forward locking stitches and to open said circuit ‘and to
cally increasing number and interconnection of the switch
return said stitch control to forward stitching position
contact groups 10-50 of the stitch selector switch C, in
upon the subsequent sewing of equal numbers of reverse
the manner shown in the drawing and understood from 45 locking stitches by said machine upon operation of the
the operation as described hereinbefore.
respective selector switch of said controller.
If it is desired to effect ‘locking of the end of a scam,
3. In a control system as claimed in claim 2, including
the monitor switch 12 is maintained in open position until
means to interrupt said counting pulses upon reaching of
shortly before the completion of the seam and closed by
the ?nal stationary contact by said movable contact means
any suitable means, such as by a timing switch or a sepa 50 of said stepping switch.
the machine in the forward stitching direction, in substan
rate stitch counter of any type designed to close the
switch 12 upon completion of a desired number of stitches
coinciding with the end position or any intermediate
point of a seam where the locking or tacking stitches are
desired,
4. In a control system as claimed in claim 3, including
further means to return said moving contact to zero posi
tion by said machine upon cessation of the operation
thereof.
5. In a control system as claimed in claim 2, wherein
55
In the foregoing the invention has been described with
reference to a speci?c illustrative device. It will be evi
dent, however, that variations and modi?cations as well
as the substitution of equivalent elements or devices for
those shown herein for illustration may be made without
said ?rst means is comprised of a cam driven from the
drive shaft of said machine, a circuit including a source
of current, and an interrupter switch actuated by said
cam to produce a current pulse during each revolution of
said machine.
departing from the broader scope and spirit of the inven
6. In a control system as claimed in claim 2, including
tion as set forth in the appended claims. The speci?ca
means to initiate said counting pulses at the instant of
tion and drawing are accordingly to be regarded in an
starting the stitching of a ‘seam by said machine, to pro
illustrative rather than in a restrictive sense.
duce a series of forward and reverse locking stitches at
I claim:
65 the beginning of said seam.
1. The combination with a sewing machine compris
7. In a control system as claimed in claim 2, wherein
ing an electrically actuable stitch control having an ex
said ?rst means is comprised of a circuit including a cur
citing circuit, to change from forward to reverse stitch
rent source and a periodic interrupter controlled by said
ing during closing of said circuit; of a control system for
machine, and a switch in series with said source and inter
automatically producing a selectable number of forward 70 rupter being normally opened and adapted to be closed at
and reverse locking stitches at a predetermined point of a
a desired instant during a stitching operation, to effect a
selected number of locking stitches at a correponding
seam being sewn by said machine comprising pulse gen
point of a ‘seam being sewn.
erating means controlled by said machine, to produce a
8. The combination with a sewing machine compris
series of electric pulses starting at the predetermined point
of said seam, each pulse representing a stitch being sewn 75 ing a stitch control, an electromagnet having an exciting
44
3,024,750
7
8
circuit and an armature connected to said stitch control,
to change from forward to reverse stitching ‘during clos
sequently open said circuit and to return said stitch con
trol to forward stitching position upon the sewing of an
ing of said circuit; of a control system for automatically
equal number of reverse locking stitches by said machine.
10. The combination with a sewing machine including
producing a selectable number of forward and reverse
locking stitches at a predetermined point of a seam being
electrically actuatable stitch control means having an
operating circuit to change from ‘forward to reverse stitch
ing vby control of said circuit, of a control system for
automatically sewing a selectable number ‘of forward and
pulses one ‘for each stitch being sewn, means to initiate
reverse locking stitches at a predetermined point of a
said pulses at the predetermined point of said seam, a
stepping switch having a control magnet with means to 10 seam being sewn by said machine comprising pulse form
sewn by said machine comprising pulse generating means
controlled ‘by said machine, to produce a series of electric
energize the ‘same by said pulses, a movable contact arm
ing means controlled by said machine to produce ‘a series
controlled by said last-mentioned magnet and a plurality
of electric counting pulses starting at the predetermined
point of said seam, each pulse representing a stitch being
sewn by said ‘machine, stepping switch means having mov
of stationary contacts cooperating therewith, to progres
sively advance said arm from one to the next stationary
contact by said pulses, a locking stitch controller com 15 able contact means controlled by said pulses and a plural
ity of cooperating stationary contacts, a locking stitch
prising a plurality of selector switches having progres
controller comprising a plurality of multiple-contact se
sively increasing numbers of multiple contacts correspond
lector switches for selecting varying numbers of locking
ing to varying numbers of locking stitches to be sewn,
stitches, and circuit means interconnecting said selector
and multiple circuit connections interconnecting said se
lector switch contacts with each other, with said stepping 20 switch contacts, said stepping switch contacts and said
circuit, whereby to operate said stitch control means from
switch contacts and with said circuit, whereby to ?rst
close said circuit and to operate said stitch control from
‘forward to reverse stitching upon the sewing of varying
numbers of forward stitches and to open said circuit and
to return the stitch control to forward stitching position 25
upon the subsequent sewing of an equal number of reverse
locking stitches by said machine by operation of the re
spective selector switch of said controller.
9. In ‘a sewing machine comprising an electrically ac
forward to reverse stitching after sewing of a predeter
mined number of forward locking stitches controlled by
the operation of the respective selector switch and to
return said stitch control means to its position for for
ward stitching after sewing of an equal number of reverse
locking stitches by said machine.
References Cited in the ?le of this patent
tuatable stitch control having an exciting circuit to change 30
from forward to reversed stitching during closing of said
circuit; a control system comprising pulse generating
means controlled by said machine to produce a series of
electric pulses one for each stitch being sewn, means to
initiate said pulses at a predetermined point of the seam 35
being sewn, stepping switch means controlled by said
pulses, having movable contact means and a plurality of
stationary contacts cooperating therewith, to advance said
movable contact from one to the next stationary contact
by each said current pulses, and multiple circuit connec 40
tions interconnecting said stationary contacts, said excit
ing circuit and said movable contact, whereby to ?rst
close said circuit and to operate said stitch control from
forward to reverse stitching upon the sewing of a prede
termined number of forward locking stitches and to sub 45
UNITED STATES PATENTS
2,005,656
2,031,323
2,418,149
Lasztoczy ___________ __ June 18, 1935
Lasztoczy ____________ __ Feb. 18, 1936
Addicks et a1 __________ __ Apr. 1, 1947
2,427,493
Bullard ______________ -- Sept. 16, 1947
2,467,422
Bruene ______________ __ Apr. 19, 1949
2,604,965
2,705,466
Schweighofer et al. ____ __ July 29, 1952
Sargrove et al __________ __ Apr. 5, 1955
2,751,868
2,759,444
2,762,961
2,853,900
2,892,526
2,906,217
Schwab ______________ __ June 26, 1956
Schwab _____________ __ Aug. 21, 1956
Colby _______________ __ Sept. 11, 1956
Hillyer ______________ __ Sept. 30, 1958
Devaud ______________ __ June 30, 1959
Mys‘ka ______________ __ Sept. 29, 1959
Документ
Категория
Без категории
Просмотров
0
Размер файла
770 Кб
Теги
1/--страниц
Пожаловаться на содержимое документа