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Патент USA US2107368

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Fe'b. 8, 1938.
N. v. cHRlsTENsEN Err AL
Filed June 12, 1936
4 SheetS-Sheeïl 1
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Norman V'L'izrLsi/‘ßlzsßn
By 7121115 we@
Feb- 8, 1938.
N. v. cHRlsTl-:NSEN ET Al.
Filed June 12,4 1936
4 Sheets-Sheet 2
Feb- 8, 1938.
Filed June 12, 1936
4 Sheets-Sheet 3
Feb. 8, 1938.
cHRlsTENsl-:N ET Al.
Filed June l2, 1956
Patented Feb. s, 193sl
Norman V. Christensen, Chicago, -and Hans
Hacklander, Tinley Park, lll., assignors to
Union SpecialMachine Company, Chicago, Ill.,
a corporation of Illinois
Application .ll’unel 12, 1936, Serial N0. 84,862
2 Claims.
This invention relates to sewing machines; and
it has reference more particularly to what are
known as “feed oiî the arm” sewing machines
wherein the work being sewed is advanced out
5 ward of a supporting arm incident to presenta
tion to the stitching instrumentalities.
In sewing machines of the type specifically re
ferred to relatively heavy rock'er arms are or
dinarily employed to convert the rotary motion
10 of an actuating shaft into back and forth move
ment of the parts, such, for example, as the
» needle-carrying bars, which require reciprocation.
The action of these rocker arms is attended by
excessive vibration and results in rapid wear of
15 saidA arms and in the'parts connected with them.
Our invention is directed toward overcomingthe drawbacks which have been pointed out, not
only for the purpose of minimizing vibration and
_the rapid wear attendant thereupon, but of mak
20 ing it possible to safely operate the machines at
much higher speeds than heretofore with a cor
responding increase in productive output.
One way in which the foregoing advantages can
'be readily realized in practice will be evident
from the following detailed description of the
(Cl. 112-63)
»vanced voutward of said arm past the .needles in
dicatedat 8 of which there are two in the present
instance. All the working parts of the machine
derive their movements either directly or indirect
ly from a main shaft 9 which extends axially
through the elevated tubular portion 3 of the
frame I and which is journaled in suitably spaced
inset bearing bushings I9, II, I2, and I3. At its
left hand protruding end, the shaft 9 is provided
with a combined hand and belt wheel I5 so that
th‘e machine can be operated'either manually or
under power. `Mounted on the shaft 9 near the
right hand -en_d are three eccentrics I6, I1 and
I8, which, through the downward strap rods I9,
20 and 2| 'respectively associated with them,
actuate the feed mechanism already referred to,
complemental ' stitch-forming
means (not illustrated) that cooperates with the
needles 8 in a well known manner within the
outer end of the work supporting arm 1. 'I'he 20
usual presser foot of the machine is indicated at
22, and as shown is secured to the lower end of
a presser bar 23 coni-ined to up and down move
ment in guide bushings 25 and 26 at the top and
bottom of the head 5. 'I‘he presser bar 23 is'
attached drawings, wherein
yieldingly urged downward by a leaf spring 21
Fig. I shows the top plan view of a feed olf the which is anchored by a stud 28 (Fig. III) pro
arm sewing machine conveniently embodying our > jecting upward from a boss 29 on the frame I and
l invention, with the top cover plate of the machine -extending forwardly along the top of the neck 4
30 removed and with portions of its frame broken and into the headl 5 through an’opening 3l) in the
away and sectioned to expose important parts back of said head. The free end of the spring 21
reaches into a longitudinal slot 3I of the bushing
which would otherwise be concealed.
25 and-bearsdirectly upon _the rounded top end
Fig. II shows the front elevation of. the ma
chine, likewise with portions broken away and of the presser bar 23 as shown in Figs. II and III.
in section to expose certain parts at the interior. A means is shown in Fig. III at 32 whereby the
Fig. III shows the elevation of the left hand pressure of the spring 21 may bev regulated. ~The
end of the machine with its drive Wheel and its` presser foot 22 may be locked ln elevated posi
work-supporting arm removed; and
tion, when required,~by means of a cam latch 33
which cooperates with a lateral projection 34 of
Fig. IV is atransverse section taken as indi
40 cated by the arrows IV-IV in Figs. *I- and' II.
a collar 35 secured to lthe presser bar 23vwithin
As herein illustrated, the machine comprises a ' the head 5. As shown in Figs. I and III, the
bracket-like frame I with a flat base 2 to rest projection 34 of the collar 35 is engaged between
upon a suitable table or other support, and with ~ a pair of guide plates 3B respectively at opposite
an integrallyformed, forwardly-projecting longi
sides of a vertical slot 31 in the outer end wall
45 tudinal tubular portion 3 at an elevation above of the head 5, to steady the presser bar 23 in its
said base. Extending laterally from the tubular ' up and down movements and at the same time
portion 3 of the machine frame at the left hand prevent rotation thereof. In order that the press
end, is a neck 4 which terminates in a vertical er foot 22 may be lifted in opposition to the spring
head 5, and pendant from the right hand end is 21 during the sewing, the machine- is fitted with
50 a boss-like projection 6 whereto is secured a work
supporting arm 1V which extends outward at an
angle with its free end underreaching the head
' 5.
By suitable feeding mechanism (not illus
a pedal control means including a rock shaft 38
which extends into the back of the head 5, and
`at its inner end has an arm 39 with a stud 49 _
which engages a vertical slot 4I in an upward
trated) within the hollow ofV the- arm 1, the work j tongue 42 añixed to the projection 34 of the collar
55 being sewed in the machine is progressively >ad- . 35, said slot 4I permitting the normal up and 55
down movements of the presser bar 23, see Figs.
I and II. A lever 43 at the outer end of the rock
shaft 38 'is pivotally connected to the upper end
of a link 45 extending downward through a clear
ance hole 46 in the base 2 of the machine frame
|.to a control pedal, not illustrated. After com
mon practice the machine is further provided
with a number of tensioning devices 41, 48, 49
and 50 for the needle and looper threads used in
the sewing, each of said devices including a pair
of friction `discs 5| (Fig. II) which are free on
the head 5 are readily accessible upon swinging
aside of a frontal protection cover plate 86 which
is attached by a thumb screw 81. _
According to our` invention, the gears 51 and
59 are made with comparatively small teeth dif
fering in number by a few odd teeth from those
of. the intervening idlerv 58 so that the shock
loads attendant upon the operation of the needle -
bar will be apportioned between the teeth of said
gears and the wear correspondingly distributed.
As a consequence of the described construction,> -
stems 52 anchored in the machine frame and it will be apparent that the functioning .of the
which are subject to regulatable springs 53. A v needle bar actuating mechanism will be smooth,
slide plate 55 (Fig. I) operated concurrently with since the weight of the link 11 is compensated
for by the balancing df the crank disc 15 and
15 the presser foot lifting mechanism, carries wedge
projections 56 for engaging between the discs 5|.
of the devices 41-59 to relieve the tension on the
Coming now to those features which constitute
20 the subject of our invention, there is secured
to the main shaft 9 immediately to the left of
its lateral thrusts nullifled through conñnement
of the stud 18 on the needle bar 86 to movement
between the guide plates 85, and since the shaft
of the crank 60 is `coordinated with the drive ^
shaft 9 through the rotary gear train 51-59, so
that the sewing machine can be safely operated
the bearing ||, a spiral gear wheel 51 which,. at high speeds without excessive noise and with
through an intermeshing idler Wheel 58, serves to
drive a similar gear wheel 59 on a short parallel
25 shaft 60 within the head 5. The shaft 6|) and
the shaft 6| of the idler gear wheel 58 are jour
naled in bearing bushings 62, 63, 64 and 65, the
bushings 62 and 64 being set into the right
hand side wall 66 of the head 5, and the'bush
30 ings 63 and 65 into the Wall of a supplemental
gear housing 61 >integrally formed with the head
5 beyond -said side wall and communicating with
a chamber 68 set apart within the neck 4 by a
cross partition 69 which supports the bushing Il
35 of the main shaft 9, and a dividing partition „
16 between said neck and head. From Fig. IV
it will be observed that the chamber 68 has a
depression 1I constituting a sump for oil which is
splashed about by rotation of the gear 51 andy
thus carried to the gears 58 and 59 as well 'as
to the bearings Il, 62, 63, 64 and 65 for the
shafts 9, 6|) and 6|. The gears 51, 58 and 59
are accessible upon removal of the cover plates 12
and 13 4respectively closing the front of the gear
housing 61 and the top of the chamber 68. As
shown in Figs. I and H, the left hand end of the
shaft 68 extends through the bearing 62 into the
hollow of the-head 5, and has secured to it a
dynamically balanced crank disc 15 whereof
50 the small diameter pin 16 is coupled, by means of
a relatively light vertical link 11, with a corre
spondingly small diameter lateral stud projec
out vibration such as would result in rapid wear.
The provisions made for self lubrication of the
needle bar actuating mechanism preclude the
necessity for any attention upon the part of the
operator except for renewal or replenishment of
the oil in the sump at very infrequent intervals.
Having thus described our invention, we claim:
1. In a feed-off-the-arm sewing machine, a
frame having an elevated horizontal portion ter
minating in a hollow head, and a work support
ing arm underreaching said head; a longitudinal
drive shaft extending along the elevated longi
tudinal frameportion; a needle bar confined to
vertical reciprocation inthe head; a needle ac
tuating shaft substantially parallel to the longi
tudinalshaft and journalled within the head; a
train of gears connecting the needle actuating
shaft with the drive shaft; operating connec
tions within the head through which the needle
bar is reciprocated from the needle actuating
shaft; and partitioning within the head setting
apart an oil chamber for the gear train to pre
vent splash oil from reaching the needle bar.
" 2. In-> a feed-off-the-arm sewing'machine,l a
frame having an elevated hollow horizontal por
tion with a laterally-projecting hollow terminal
head at one endthereof, and a work supporting
arm underreaching said head; a longitudinal
drive shaft journaled within the horizontal por
tion of the machine frame; a needle bar con
tion 18 of a collar 19 on a bar 86 which carries fined to vertical _reciprocation in the head; a sub
the needles 8, said bar being confined, like the. stantially parallel needle-actuating shaft in the
presser bar 23, to vertical axial reciprocation by horizontal plane of the drive shaft and» journalled
guide bushings 8| and 82 set respectively into within the head; a train of gears connecting the y
needle-actuating shaft with the drive'shaft; op
the top and bottom of the head 5. ‘ The outer
end of the stud 18 on the collar 19 -is ñattened at erating connections through which the needle bar
opposite sides, as at 83, and engages between a is reciprocated from the needle-actuating shaft;
and partitioning within the head setting apart an
60 pair of vertical guide plates 85 secured to the oil chamber for the gear train to prevent splash
inner side of the wall 66 ofthe head 5 ,(see Figs.
I and Il) to restrain the needle bar 80 against oil from reaching the needle bar. _
rotation and to take the lateral thrusts of the
link 11. The various parts within the hollow of
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