US2249284A - Sewing machine - Google Patents

Description

july 5, 1941.

N. V. CHRISTENSEN SEWING MACHINE Filed July 25, 1958 www A TTORNEYS.

July l5, i941. N. v. cHRlsTENsEN 2,249,234

- SEWING MACHINE Filed July 25, 1958 4 Sheets-Sheet 2 INVENTOR:

W5/.6545. BY @d July l5, 1-941. N. v. cHRls-rENsEN 2,249,284 i SEWING MACHINE Filed July 25, 1938 4 Shets-Sheet 5 k *l WITNESSES: 7 P' INVENTOR;

July 15, 1941., N. v. cHRlsTENsEN l 2,249,2.84

SEWING MACHINE Filed Ju1yv25, 1938 4 Sheets-Sheet 4 al man W l TNESSES: INVENTOR:

. BY @aud/@Ml ATTORNEYS.

Patented July 15, 1941 SEWING MACHINE Norman V. Christensen, Chicago, Ill., assgnor to Union Special Machine Company, Chicago, Ill.,

a corporation of vIllinois Application July 25, 193s, serial 10.221.013

(ci. 11a-197) 9 Claims.

'I'his invention relates to sewing machines. More particularly it has reference to commercial sewing machines of a type especially useful for edge seaming `operations such as forming inseams and outseams of trousers, unitingthe edges of fabric blanks in the manufacture of bags, and

similar operations where through and 'throughA stitching is desirable. In certain of its aspects, however, the present improvements are not necessarily` coni-ined to sewing machines of the special type specifically referred to.

My invention is concerned with changes and refinements which are conducive to the attainment of higher operative efficiency vin sewing machines with corresponding increase in output or production from them; and which moreover favor the attainment of greater structural compactness in such machines. in practice as hereinafter more fully explained by simplifying and closely coordinating the needle actuating, the complemental'stitch-forming, and the feeding mechanisms of a sewing machine in such a way that they can all be operated from a single drive shaft and for the most part enclosed within a housing or hollow frame of small dimensions for protection against accumulation upon them of dust, lint or other clogging matter, and forthe purposes of automatic lubrication with oil elevated or thrown up by splash or spray action. l

Other objects and attendant advantages will appear from the following detailed description of the attached drawings, wherein Fig. I shows, in longitudinal section a sewing machine conveniently embodying my inventio-n.

These advantages I realize partition 6 with a forwardly-extending offset at l. Rising from the base at one end in the' longi tudinal center of the machine is a relatively low hollow standard 8 with a rearwardly sloped back wall 9 in integral continuation with the rear end wall 5 of the base 'I, a. vertical front wall III in integral continuation with. the transverse partition 6,' and vertical side walls II, I2 which are closely spaced as compared with the side walls 2, 3 of said base. The top of the base I? is formed by a generally U-shaped horizontal work supporting plate I3 which extends beyond the side Vwalls 2, 3 and the front end wall 4 of the base hang constituting a guide head for the needle and y presser bars of the. machine which are respectively designated I1 and I8. The work supporting plate I3 nts against and is iiush with a horizontal rectangular web I9 which is integral with the standard 8 and' which extends forwardly and laterally respectively from the front wall I0 and the side walls II, I2 of said standard, see Figs.'I

Fig. II shows the machine in front'elevation with the cover plate removed from thefront of the needle head.

Fig. III is a staggered horizontal sectional view taken .as approximately indicated by the broken dot and dash arrowed line III--III in Fig. I.

Fig. VII is a fragmentary view in side elevation looking as -indicated by the arrows VII-VII in Fig. II.

As herein illustrated, my improved sewing machine has a' hollow rectangular base I integrally formed with longitudinal side walls 2, 3, front and rear end walls 4, 5 and a medial transverse lwardly into the side and end walls 2--5 and the partition 6, see Fig. I. As a consequence of this construction, there are formed at the bottom of the standard a closed chamber 25 which is kept filled with oil to the level indicated at L, and a partly closed compartment 26 for the comple.

mental stitch-forming and feeding mechanisms of the machine whichwill be presently described.-

The oil in the chamber 25 may be replenished either upon withdrawing the slide 2| in the top plate I3 or upon removing a plug shown at 21 in Fig. I from an opening 28 in the rear end wall 5 of the housing.

All the moving parts of the machine are actuated from a single rotary shaft 29 which extends longitudinally through the hollow base I and which is journaled in ball bearings 30, 3|, and 32 set in-to the walls 4, 5, and in the partition 8 respectively. The opening for the bearing 8| is 'closed by a removable plate 33 which has an in- 38 of the head I 5. Confined to endwise reciprocation in bearing bushings 39, 45 set into the top 4| and the bottom 38 of the` overhang l5 in parallel relation to the needle bar I1 is a slide rod 42. In the interval between the bushings 85 and 40, the rod 42 carries a rotatively adjustavble connecting member in the form of a bracket 43 with a laterally projecting pin 44 which telescopically engages with a sliding fit, into the transverse bore of a member45 secured to the top end of the needle bar I1. As shown, the hub of the bracket 43 surrounds the slide rod 42 and has a set screw 43a by which said bracket can be fixed in rotatively adjusted positions. Due to the looseness of this connection, compensation is automatically made for lack of absolute parallelism between the needle bar I1 and the slide bar 42 with attendant avoidance of binding strains. This feature is highlyI advantageous in productionin that it allows for slight variations in the spacingof the bars in different machines. At the lower end of the slide bar 42 is a clevis 45 which is pivotally engaged by the upper end of a pitman 41 whereof the lower end engages a crank 48 on the drive shaft 219. l

The presser bar I8 is confined to endwise movey ment in bearings 49, 58 respectively at the top projection 54 on ya collar 55 on said bar with a longitudinal slot in the lower end of Aa guide member 55 which depends from the needle head I5.and. which is securedbya set screw shown at 51 in Fig. II. The presser bar I8 is liftable against the action of the spring by means of a horizontal lever 58 (Figs. II and VII) fuicrumed on a stud 59 at one side of the standard 8, said lever being connected, by means of a short vertical link 50 with a collar 55. 'Ihe opposite end of the lever 58 is apertured as at 5| for connection by a rod or chain (not shown) with a foot treadle.

The complemental stitch forming mechanism of the machine includes in this instance a looper 52 which cooperates witha needle 53 in the lower end 'of the bar |1, beneath the work supporting plate I3. As shown the looper. 52 is mounted in a holder 54 secured to a pin 55 whereof the opposite ends are pivoted in upstanding bearing ears of a yoked rocker 65. As further shown the rocker 55 is affixed to ay rock shaft 51 which extends transversely of the machine and which is journaled in bearings 58,59 and 10 respectively set into theside wail 3 and the side walls of the forward offset 1 yof the chamber 25 within themachine base I. The looper 52 receives loop taking and loop sheddingmotions in a direction transversely to that of feeding shown by the arrows in Figs. II and IV, as a consequence of oscillation ofthe shaft 51 induced through an arm 1I, and a coupling link 12 from an eccentric 18 on the drive shaft 29 within the chamber 25.

Needle avoiding movements are induced in the -looper 52 in the direction of feeding through rocking of the latter about the axis 55, such movement being imparted through a rod 14 which connects the looper holder 54 to another eccentric 15 on the shaft 29. y

'I'he function of advancing the work across the plate I3 as indicated by the arrows in Figs.

II and IV is vested in a feed dog 18 which is mounted on a carrier bar 11. As shown in Fig. IV, the carrier bar 11 is yoked at its front end to clear the drive shaft 29 within the compartment or subdivision 25 of the base I, said dog being secured to the upper or overreaching extremity 11a of said yoke. At its rear end, the feed bar 11 has a pivotal connection 18 with the top end of a rocker 19 which is secured to a-rock shaft journaled in spaced bearing lugs 8| and 82 on the base I. A horizontal arm 83 clamped to an outwardly extending stud 84 on the rocker 19 is coupled, by means of a drop link 85, with an eccentrically disposed pin 85 on a crank disk 81 at the front end of the drive shaft 29 exteriorly of the chamber 25. 'I'he crank' piny 85 is adjustable radially of the disk 81 by a screw shown at 88 in Fig. V, and is securable in adjusted positions by a clamp nut 89 Vin a well known manner. Through the connections just described, it will be evident that during each rotation of the drive shaft 29, the feed dog 15 will be reciprocated horizontally to perform a feeding movement. The feed dog -18 derives its up and down or lift movements from an eccentric 88 on the drive shaft 29 within the compartment 25, the strap 9| of said eccentric being pivoted at 82 to the underreaching extremity 11b of the feed bar, see Fig. IV.

Mounted on the drive shaftl 29 within the chamber 25 immediately adjacent the ball bearing 8| is a disk 95 which dips into the lubricant L in the sump at the bottom of thechamber 25. As the drive shaft 29 rotates, oil is carried up bythe 'disk 55 and impinges upon the inner facev of the sloping rear wall 9 of the standard 8, lsome of the oil so elevated being projected forwardly into the head I5 by the deilecting action ofsaid wall to lubricate the bearings for the needle bar I1 andpresser bar I8, and the rod 42, while the rest drops onto the bearings for the rods 41 and 12'as well as vthe bearings for the shaft 51 to which the arm 1| is secured. Part of the sprayed oii also serves to lubricate the ball bearings 3| and 32 for the drive shaft 29.

From the foregoing, it will be apparent that I have provided a simple compact sewing machine with a minimum of moving elements which are small and light in weightto the end that the machine can be run at top speeds without excessive vibration. Due to being for the most part enclosed within the framework of the machine. the various moving elements-are protected against clogging by lint and dust while .oil is constantly sprayed upon them to keep them well lubricated.

Having thus described my invention, I claim:

1. A sewing machine comprising a horizontal work support with a standard rising therefrom and having at its top a lateral projection which over-reaches'the work support; a needle bar guided for up and down movement on the lateral projection of the standard; a horizontal drive shaft journalled beneath the'r work support; and needle bar operating mechanism including a slide bar which is parallel with said needle bar and which is guided for endwise movement on the standard, a bracket with a boss surrounding the slide bar and a lateral projection engaging, with capacity for free lengthwise sliding movement, a

member aiixed to the needle bar, means for securing the boss of the arm to the slide bar with capacity for rotative adjustment of said arm about said slide bar, and a rotary actuator on the drive shaft for imparting reciprocatory movement to the slide bar.

2. A sewing machine comprising a horizontal Work support with a standard rising therefrom and having at its top alateral projection which over-reaches the work support; a needle bar guided for up and down movement in the lateral projection of the standard; a horizontal drive shaft journalled beneath the work support; and needle bar operating mechanism including a slide bar parallel with said needle bar, connecting means extending crosswise lbetween the needle bar and the slide bar including a pair of components, one secured to theneedle bar and the other to the slide bar and telescopically engaged with each other, a. crank on the drive shaft, and

a pitman connecting the slide bar with the crank. f 3. A sewing machine comprising a frame withA a hollow base whereof the top constitutes the Work support, and a communicating hollow standard rising from the base and terminating at the top in a lateral houow communicating head which over-reaches the work support, the

rear Wall of said standard being inclined upwardly and forwardly toward the head; needle actuating mechanism within the head; and means taking oil from a supply in the base and impinging it upon the inner surface of the inclined rear wall of the standard for dispersion within the machine frame and for deflection of some of the dispersed oil laterally into the needle head to lubricate the needle actuating mechanism.

4. A sewing machine accordingto claim 3, in which the needle actuating mechanism includes a vertical needle bar confined to endwise movement in the head, a parallel bar guided for endwise movement within the standard, horizontally telescoping means connecting the two bars at the top, and means operated from within the base and connected to the lower end of the parallel bar to reciprocate it.

5. A sewing machine according to claim 3, in which the needle actuating mechanism includes a vertical needle bar conned to endwise movement in the head, a parallel bar guided for endwise movement within the standard, horizontally telescoping means connecting the two bars at the auxiliary compartment and partly within it by is operated from the which the feeding element drive shaft.

7. A sewing machine according to claim 3, wherein the base is subdivided by a partition into A a compartment which contains the lubricating oil, and an auxiliary compartment-through both of which compartments a rotary shaft extends; and further comprising a looper within the auxiliary compartment; and connections including a roel:- shaft which extends through the partition whereby the looper is actuated by means on the rotary shaft within the lubricant compartment.

8. A sewing machine comprising a hollow base with a transverse partition setting apart a chamber which contains a lubricant and an auxiliary chamber, said partition having an offset longitudinally of the base forming an extension of the lubricant compartment; a horizontal rotary shaft extending through both compartments; a transverse rock shaft journalled-in and extending from within the lubricant compartment through one of the walls of the offset into the auxiliary compartment; a looper within the auxiliary compartment -operated from the rock shaft; and means within v the lubricant compartment whereby the rock shaft is actuated from the rotary shaft.

9. A sewing machine comprising a hollow base with a transverse partition setting apart a chamber which contains a lubricant and an auxiliary chamber, said partition having an offset longitudinally of the base forming an extension of the lubricant compartment; a horizontal rotary shaft extending through both compartments; a transverse rock shaft journalled in and extending from within the lubricant compartment through one of the walls of the offset into the auxiliary compartment; a looper within the auxiliary compartment; a bracket arm on the rock shaft within the l auxiliary compartment on which the looper is pivoted for swinging movement; a rotary actu- .ator on the rotary shaft within the auxiliary com-

Images