US2107368A - Sewing machine - Google Patents

Description

Fe'b. 8, 1938. N. v. cHRlsTENsEN Err AL 2,107,368

lSEWING MACHINE Filed June 12, 1936 4 SheetS-Sheel 1 l n Q L n n 1 [NVEAiToRs Norman V'L'izrLsi/lzsn By 7121115 we@ TToRNEYs @Qw Mam,

Feb- 8, 1938. N. v. cHRlsTl-:NSEN ET Al. 2,107,368

SEWING MACHINE Filed June 12,4 1936 4 Sheets-Sheet 2 FIG. 1

INVENTORS:

ORNE YS.

Feb- 8, 1938. N. v. cHRlsTENsEN ET AL 2,107,368

SEWING MACHINE Filed June 12, 1936 4 Sheets-Sheet 3 ORNEYS.

Feb. 8, 1938. N. cHRlsTENsl-:N ET Al.

SEWING MACHINE Filed June l2, 1956 Patented Feb. s, 193sl NETE- TATES Hacklander, Tinley Park, lll.,

assignors to Union SpecialMachine Company, Chicago, Ill., a corporation of Illinois Application .llunel 12,

2 Claims.

This invention relates to sewing machines; and it has reference more particularly to what are known as feed oi the arm sewing machines wherein the work being sewed is advanced outward of a supporting arm incident to presentation to the stitching instrumentalities.

In sewing machines of the type specifically referred to relatively heavy rock'er arms are ordinarily employed to convert the rotary motion of an actuating shaft into back and forth movement 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 saidA arms and in the'parts connected with them.

Our invention is directed toward overcoming arm sewing machine conveniently embodying our l invention, with the top cover plate of the machine removed and with portions of its frame broken away and sectioned to expose important parts which would otherwise be concealed.

Fig. II shows the front elevation of. the machine, likewise with portions broken away and in section to expose certain parts at the interior. Fig. III shows the elevation of the left hand end of the machine with its drive Wheel and its` work-supporting arm removed; and

Fig. IV is atransverse section taken as indicated by the arrows IV-IV in Figs. *I- and' II.

As herein illustrated, the machine comprises a bracket-like frame I with a flat base 2 to rest upon a suitable table or other support, and with an integrallyformed, forwardly-projecting longitudinal tubular portion 3 at an elevation above said base. Extending laterally from the tubular portion 3 of the machine frame at the left hand end, is a neck 4 which terminates in a vertical head 5, and pendant from the right hand end is 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- 1936, Serial N0. 84,862

vanced voutward of said arm past the .needles indicatedat 8 of which there are two in the present instance. All the working parts of the machine derive their movements either directly or indirectly 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 the 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, and a suitable 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 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 movement in guide bushings 25 and 26 at the top and bottom of the head 5. 'Ihe presser bar 23 is' yieldingly urged downward by a leaf spring 21 which is anchored by a stud 28 (Fig. III) projecting upward from a boss 29 on the frame I and extending forwardly along the top of the neck 4 and into the headl 5 through anopening 3l) in the back of said head. The free end of the spring 21 reaches into a longitudinal slot 3I of the bushing 25 and-bearsdirectly upon the rounded top end of the presser bar 23 as shown in Figs. II and III. A means is shown in Fig. III at 32 whereby the pressure of the spring 21 may bev regulated. -The presser foot 22 may be locked ln elevated position, when required,-by means of a cam latch 33 which cooperates with a lateral projection 34 of a collar 35 secured to lthe presser bar 23vwithin the head 5. As shown in Figs. I and III, the projection 34 of the collar 35 is engaged between a pair of guide plates 3B respectively at opposite sides of a vertical slot 31 in the outer end wall of the head 5, to steady the presser bar 23 in its up and down movements and at the same time prevent rotation thereof. In order that the presser foot 22 may be lifted in opposition to the spring 21 during the sewing, the machineis fitted with 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 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 clearance hole 46 in the base 2 of the machine frame |.to a control pedal, not illustrated. After common 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 stems 52 anchored in the machine frame and which are subject to regulatable springs 53. A slide plate 55 (Fig. I) operated concurrently with 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 threads.

Coming now to those features which constitute the subject of our invention, there is secured to the main shaft 9 immediately to the left of the bearing a spiral gear wheel 51 which,.

a chamber 68 set apart within the neck 4 by across partition 69 which supports the bushing Il 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 the small diameter pin 16 is coupled, by means of a relatively light vertical link 11, with a correspondingly small diameter lateral stud projection 18 of a collar 19 on a bar 86 which carries the needles 8, said bar being confined, like the.

presser bar 23, to vertical axial reciprocation by guide bushings 8| and 82 set respectively into the top and bottom of the head 5. The outer end of the stud 18 on the collar 19 is attened at opposite sides, as at 83, and engages between a pair of vertical guide plates 85 secured to the inner side of the wall 66 ofthe head 5 ,(see Figs. I and Il) to restrain the needle bar 80 against rotation and to take the lateral thrusts of the link 11. The various parts within the hollow of 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 differing 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,

it will be apparent that the functioning .of the v needle bar actuating mechanism will be smooth,

since the weight of the link 11 is compensated for by the balancing df the crank disc 15 and its lateral thrusts nullifled through connement of the stud 18 on the needle bar 86 to movement between the guide plates 85, and since the shaft of the crank is `coordinated with the drive shaft 9 through the rotary gear train 51-59, so that the sewing machine can be safely operated at high speeds without excessive noise and without 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 terminating in a hollow head, and a work supporting arm underreaching said head; a longitudinal drive shaft extending along the elevated longitudinal frameportion; a needle bar confined to vertical reciprocation inthe head; a needle actuating shaft substantially parallel to the longitudinalshaft and journalled within the head; a train of gears connecting the needle actuating shaft with the drive shaft; operating connections 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 prevent splash oil from reaching the needle bar. 2. In a feed-off-the-arm sewing'machine,l a frame having an elevated hollow horizontal portion 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 portion of the machine frame; a needle bar confined to vertical reciprocation in the head; a substantially parallel needle-actuating shaft in the horizontal plane of the drive shaft and journalled within the head; a train of gears connecting the y needle-actuating shaft with the drive'shaft; operating connections 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 prevent splash oil from reaching the needle bar.

' NORMAN V. CHRISTENSEN.

HANS HACKLANDER. Y.

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