US2334822A - Sewing machine - Google Patents

Description

Nov..23, 1943. H. HER'II'ZBERGER v SEWING MACHINE Filed Dec. 8, 1941 INVENTOR fl'crm'arz HZWZk/yer BY 7 W ATTORNEY Pa se Nov. 23, 1943 a snwrno monlnsfl 3 it f Herman e tage; New York, N. r. V

= it Application Dcemlier8f1941', Serial 1 "InGonnany Jul y 3, 1941 This-invention relates to sewieg aehmes, and

more particularly to a novel attetnmefitr r sew:

i n s r sub o i ent Jd sse the needle from pthe; worlclvwhen the-mac ine is stopped l The device offthefin ve articularly defsigned for use in 'conne'etion With sewing-' ma chines whichimake about 3990 stitches perfr ninie an or u l sewi a ii n sb t i type ,are d riven by fan lelectric 'ro'otorfand are;

used' in the textile-industry.

"Frequently numberffoffparallel rows. "of stitches must be sewedonthe.sameigoods; Every timea row has'been finished the sewing machine must be stopped." "Then" the worker-mist diseng gagejthe needlefromfthe work before, he can start with the next row ofistitohes. Crenerally this is-Idone by rotating the balance wheel of I wherein;

beerr stopped, 1 V i Ajfurther object of the invention is to provide from 'the 'work after the sewin'g' machine has an apparatus whichffirst switches off the electric drive motor'of thesew ing machine andfth'en automatically disengages the needle from i the 1 rhe eanurur ner objects 'of'the invention {will become more apparent 'fwhen the description proceeds taken Fig. 1 is 'a schematicside View taken from th I left-hand side of a sewingm 1:

the sewingmachine, and to this end the'worker must remove onehandfrornthe work. The inventor'has found that'if the, time required for sewing an open lining is for instance54 seconds then 16 seconds are required for disengaging the needle from the work. v s V In accordance with the invention this drawbackis removed. The machine of the invenj tion comprises a device for automatically disengagingthe needle from'the work after the' sewing machine has been stopped or nearly: brought to a standstilL; Preferably, the device of the invention is actuated by th foot or the {Fig 2 isa schematic sideyiew taken fromthe right ha'nd' side of asewing machine trating the device of l the invention. i

Referring to thefdrawing'; thelsewing machine comprises amain drive shaftdirbearing aorank ll connectldjwith connecting 'rod l2 driving' in turn' c'rosshead i3. -"Crosshead i3- is guided in bearing ll' and bears needle-l5', "removably se cured by screw I6. The'work I1 is supported on table I 8. wheel 20 driven'by electric motor 2| by means of belt 22. I

It will 'be evident that whencrank ll is in V any position within the angl indicated. at a,

needle l5 will bedisengaged from work I'L *Only knee of. the operator so that he can use both hands for holding and moving the work.

' Preferably the device 0f the invention. is connected with a switch for switching on the drive' motor of the sewing machine. By actuating for instance a foot pedal the switch'isfirst actuated;

for disengaging the needle'from the :work};

and then the device of the invention is' released, 7

. In a preferred embodiment of the invention the balance wheel of the sewing machine. which is secured to the main drire-sh'aft has 'aimembers depending therefrom which may .for .instancebe. 'a stud. This stud is adapted to cooperate with a member such as a plate which, is normally below the balance whee]. When the-drive motor 7 of the sewing machine is disengaged-this;plate is lifted to'engage the stud Thus the balance wheel is rotated until. the needle is disengaged,

from the work.

7 It is accordingly anobl'ect of the invention to rovide anovel attachment for sewing vmachines.

V Anotherobject of the invention is to provide. a device for automatically disengaging the needle when crank H is in aposition below angle a,

needle l5 pierces work ll. In order to disengage the needle from the work it is therefore only' necessary to bring crank within angle a.

ll into any position To this end balance wheel 23 secured'to main shaft Hi is provided with stud 24. Preferably, 7' stud 24 is arranged so that it is aligned with" crankll. Stud is adapted tocooperate with plate 25 which is urged'f downwardly by springs 26, 26. Springs 28, 25am secured to base 21 supported by a frame work 28. 1 Plate 25.has a dependingrod 3!].guided in bearing 3|. Rod 30 is adapted to be lifted by cam32 secured to shaft 33. Lever 34 issecurd to shaft 33 and base; I pin-engaging slot '35 in lever 36. 1 The lower end g of lever 36 is secured to foot pedal Slat 38, Pedal 3! has its fulcrumatfl where it is secured to ,frame work ,28 Spring 4| urges pedal 31 upwards into its dotted position 31a. Switch lever 142 has a'lost-motionconnection with rodfifiiand actuates switch 43; current is conducted to the switch by wires 44; Switch lever iZ carried at 'its one end a contact segment 53. The current i is conducted through wires. 7

connected with wires 5i and 52 leading to'terminals 50 andf55.

These wires are in connection with the drawing;

and illust Driveshaft I 0. has secured thereto:

" The operation of my novel device will now be evident. Normally foot pedal 31 is in the dotted position 31a. Cam 32 is in its dotted position 32a and is not in engagement with rod30. Hence springs 26 are free to pull plate 25 against bear:

'ing 3| Motor 2| is energi'zedwhen the switch lever is in its position indicated at 42a.

When it is desired to stop the sewing machine and to disengage the needle, the. operator) pressesdowniootjbedal 3'la which now moves into the full-line position 31. This causes a downward movement of switch lever 42a for switching off v.

motor 2|. Due to the lost-motion connection between rod 36 and crank 34 the latter does not start to move until motor 2| has .beenswitched off. Further downward movement of pedal 31; causes rotation of cam 32a'into its full line posij Now plate i 25 brings stud 24 intothe position shown in tion.32 which causes lifting of rod 30.

' tion without-departing from the broader-spirit andscopethereof, assetforth-in the following:

claimsiy I claim: v

'1. In.a sewing machine. having a main shaft,

an electric motor for driving said shaft, a,bal-- ance wheel-onsaid shaft, and a needle-operatively connected with a said shaft and reciprocated thereby, a switch forsaid motor,- a-device for automaticallydisengaging said needle includingwanv element extending from -said-lbalance wheel; a plate normally arranged belowsaid ele-= mentga cam arrangedto lift said-plate-on rotation'thereof, a foot pedal operatively connected with said cam by a lost-motion connection and] v I connected with said switch for actuation thereof whereby when said pedal is movedv said switch is switched off and said plate is engaged with said element,

,2. In a sewing machine having a main shaft, an electric motor for driving said shaft, a switch 1 for said motor, a balance wheel on said shaft,

and a needlepperatively, connected-with said, shaft and reciprocatedthereby, a device for automatically disengaging said-needle including a stud on said balance wheel, aid stud having 'a predetermined position, a plate normally arranged' below said stud, a spring urging said plate away from said stud, a cam arranged to lift 1 said plate on rotation thereof, a foot pedal, a rod connectedwith-said foot pedal and having a lost-motion connection with said cam, said rod being connected with said switch for actuation I thereof, whereby actuation of said pedal causes first switching oif of said switchand thereafter rotation of said cam. .7 I 1 -3. Ina sewing machine having a main shaft,

an electric motor for driving said shaft, a switch for said motor, a balance wheel on said shaft,

and a needle operatively connected. with said shaft and reciprocatedv thereby, a device iori automatically disengaging said needle including'a stud 'on rsaidbalance wheel having a prede termined position, a plate normally arrangedbelow said stud and having a projection in its center, a spring for-urging said plate-away from 7 said stud, a cam arranged to lift said plate on' rotation thereof, a foot pedal operatively COD-r nected with said cam by a lost-motion connection and connected with said switch for actuation thereof whereby movement of said pedal. causes.

switching off of said switch and lifting of-. said plate into engagement with said-stud. I

' HERMA HERTZBERGERQ 7

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