US2465465A - Link-and-link machine - Google Patents

Description

March 29, 1949. c. F. MILLER 2,465,465

v LINK-AND-LINK MACHINE Filed Nov. 15, 1945 2 Sheets-Sheet 1 .llll

A4; ATTbRNEYS Mmh 29, 1949. c. F. MILLER 2,465,465

LINK-AND-LINK MACHINE Filed Nov. 13, 1945 2 Sheets-Sheet 2 k Wz Q 1 i 1 i g\ Q N. g Q f g Q l g Q I I I I INVENTOR. M54414 6 8 ATTORNEYS Patented Mar. 29, 1949 UN- l TED "STATES PA I' E N T F Fl CE LINK-'AND-LINK 'MAGHIN E Charles: F. Miller; Philadelphia; Pa., assignor' to Jacquard Knitting-Machine Co.,"Inc.,* Philadelyphia; Pa., a corporationof New York zApplication November 13, 1945, Serial No. 628,229

' SICIaims. Ll

I As is well. known, knitting machines ,of "the .links-and-links type employ double ended. needles, i. e. needles havingahookatea'ch end and 'jacks to operate these needles in forming. stitches and in passing. from one .needle.bed to the other and (usually-at =least) back again. ..Speaking generally,- the jacks grasp the. hooks. of the needles and fortthe-most part aremovedlongitudinally by-cams acting: on butts. projecting;v from 1 the jacks. tThe actionof suchcams may be sup- 1 plemented however by pattern mechanisms, .by supplemental jacks acting on the jacks which engage the needlesjetc. .sometimeseach needle jack is composed: of, say,. two separate parts, for rexamplezofaa needle-pushing. portion and a separate hook portionto engage over the needlehook topull its-needle. .For. brevity, theword l To release needle from-jacks when needleslare to be-Jtransferred from one needlelbed'to the other; the head or needle ends'of those -jacks.are. .lifted from their-bed,.and' verytcommonly and -perhaps substantially universally-in practice, this is done by means of extensions from theneedleor Hhead ends-of the jacksland cooperatingjack-lifting'r members which movelalong. the needle beds with the-feeds forengagement by the jack ends. The action. is-- a camming action, and. suchsj ack- .:lifting-membersuwear; relatively. rapidly because .their jack engaging ,surfaces ...are necessarily r'rather small; and, since there-:is. not more than one' jack-liftingmember. per. feed for each needle bed; each jack-lifting member. is struckbyand called on =tolift many 'ja'cks in eachdays work.

- Further," the jack-lifting members must .actuate the jacks within. close limits; wear of only a very small fraction. of an inch may cause. a failure 1 that results-in'damage to the machine requiring stoppage'of'thework untilthe cause; of the failure isfoundzandrepairs. requiring some time: are made. :As is well-known these Jack-lifting .mem-

here are: a source 1 of considerable trouble.

This invention relates .to needle Jacks and, op-

erating means for them that eliminate thistrouble to a considerable degree at least.

.- Briefly-. to this:end. I provide-a recess atthe back 'of' the tail end-0t each jack .(by which I meanjacks that maybecalled on to release needies) and preferably one extending for some dis- ":t'ancei tai'lward. fromnnear the :ja'clt butt 1 through 'which-...thev :camsrpperate theejack, Withf-this; I

provide, at each station where a jack may be requiredto release aneedl l'a cam to depress the tails of .jacks that are to release their needles and thus rock those'jacksto raise their heads from the needle hooks. "I'he cam need be only .aboutlong. enough lengthwise or circumferentiallyof the. needle bed, to hold ,a-jack, rocked until it, or its opposing jack in the opposite needle bed,', has been moved so" far (or1both of .those jacks have been, moved, so. far) that returning ,the needle ,-releasing jack toitsinitial unrocked position lwillhnot rep-engage it with the adjacent hook of its needle again. 'Conceivably such a cam; can..be movable. into. and, out of action, and .thus brought intog-actionpnly at times appropriate' to :cause, release .of needles. "Preferably .however, I mount such tailcams in fixed positions .in the, cam systems and atjfixed distances from the space for the fabric between the needle beds, and provide the tail of each jack with a butt that is brought, to the path of a tail cam only when the l jack is V'brought ,to .its needle-transferring -position,,e., ,g j,is projected extraffar as it were;

.in ,ithe-alternative, reach jack m ay be provided witha, recess as, it were, through which the tail cam orucamscan. pass without striking the jack so' long as the .jackis standing or moving in any ,of (its non-transferring positions; inv actuality these twoare the same. j At the' head end of.-,a bank ofj jaicks amember or members forming'a ,cam. race and/or holding the .jacks in their slots,

.may'be. recessed to. permit the outward move- Till .ments ofjthehead endsof the jacks that release the needles, or, port-ionsof the outer edges of the jacksmay be. recessed; to ,permit this, outward in .theilatterg case the recesses in the jacks may .be. inclined lengthwise of the jacks sothat enrocks .the .J'a'ck-backjto its .initial position. 301, ,the jacks. mayibe rocked back to theirinitial positionsuby action on their tails or, in some other .By suchan arrangementit-is possible to have every needle held firmlyby at, least, one jack at all times: and to have everyjackpandneedle fully confined. in. a slot ina needle. bed at all times.

fore to rock needle jacks by means of cam elements working on the outer edges of the jacks at both the head and the tail ends. In this prior arrangement however the jacks are within the path of the jack-rocking cams at all times, rather than only when needles are to be transferred from one bed to another, and for considerable periods the needles are not confined to their slots by either of their jacks. Further. a complex form of jack (composed of two separate parts, one rocking on another) is employed, and apparently it is required except in exceptional instances. With my arrangement however a jack may consist Wholly of a single piece of metal as before indicated, and every needle can be confined to a slot in the needle beds by at least one jack at all times.

The accompanying drawings illustrate the preferred form of my invention applied to a simple current form of links-and-links circular knitting machine. Fig. 1 is an elevation of the cam system as seen from inside the machine and opened out fiat, or it may be a section of the cam system equal in length to one feed length of the machine if the machine has two or more feeds. Fig. 2 is an elevation of the needle jacks employed. Fig. 3 is an elevation of a needle. Fig. 4 is a section of the camming at the line IVIV of Fig. 1. Fig. 5 is a section on the line V-V of Fig. 1 showing the tail cam. Fig. 6 is a vertical section of a part of one side of the machine about on the line VIVI of Fig. 1. Fig. 7 is a possible modification of a detail.

As is common practice, two coaxial cylinders I and 2 form the needle beds of the machine. These are slotted lengthwise externally to receive the needles and needle jacks, and are spaced apart at 3 to permit the passage of the fabric from the needles to the interior of the lower cylinder l as the fabric is formed. Forecuts attached to the adjacent edges of the needle cylinders are shown at 4. Cam cylinders 5 and 6, one mounted outside each needle cylinder, Fig. 6, carry the members of the cam system shown in Fig. 1. For simplicity of description it will be assumed that the needle cylinders I and 2 are stationary and that the cam cylinders 5 and 6 rotate about them, although the opposite may be the case in any instance as will be understood from prior practices. The latch needles I (Fig. 3) may be conventional; being double ended, i. e. having a loop-forming hook and latch at each end, they are transferable by endwise movement, from one bed I to the other 2 and vice versa, as is distinctive of links-and-links machines.

As common, two needle jacks 8, one in each needle bed I and 2, are provided to operate each needle 1; the lie in the slots of their respective needles and for the most part the members of the cam system lie close to the outer edges of the jacks so as to confine the jacks in their slots (and therewith the needles as will be understood from what follows), as indicated at the upper end of Fig. 6. These jacks 8 are substantially straight members as shown in Fig. 2, and are of an appropriate thickness as will be understood from prior practices. The head portion of each of these jacks has a shoulder 9 to engage an end of a needle for pushing the needle, and a projection III, in the form of a hook or otherwise, to pass over a needle hook whereby the jack can pull the needle (see Fig. 6). Also at a point removed from the head portion each jack has a butt II for engaging in the cam races whereby .the jack (and therewith its needle) is actuated.

The foregoing regarding jacks is substantially conventional. In addition however the jack 8 is provided with a tail portion I2, which places its operating butt II at a mid-portion of the jack as it were. The back of this tail portion is cut away to provide a recess at I3 to permit the jack to be rocked in its slot to the extent necessary to carry its hook-engaging portion Ill completely out of the hook recess in which it may be engaged, as shown in Fig. 6. Preferably the recess is so placed that the rocking is about a fulcrum near the operating butt II, say about as shown. It is evident that the recess or cutout I3 may be of any one of various shapes and sizes; substantially any shape and size is satisfactory that will permit the jack to be rocked to remove its projection ID from its needle. Also each of the jacks 8 is provided with an outwardly projecting butt I4 on its tail portion I2. Preferably the outer edge or face of this butt I 4 is on about the same line as the outer edge I5 of the jack, so that for the most part the outer edge of the butt I4 also remains close to the inner faces of cam members. Between the butts I I and It the outer edge of the tail portion I2 of the jack is depressed as it were, so that the cams I5 and 52, which project inwardly from the cam system, can pass over the jacks at this region (or be passed over by the jacks, if the machine is one in which the needle cylinders rotate) without striking the jacks. The walls of the needle-and-jack sl-ots may be cut out locally at the Paths of these tail cams as indicated at I9 in Fi 6 to permit such cam's to extend into the slots. In the present instance the ta l cams I6 and 52 (and others if there are any) are fixed in position in and with respect to the cam system and at fixed distances from the fabric space 3 between the needle beds, and the tail portions I2 of the jacks are of such lengths that the tail butts I4 remain outside the path or paths of the cam IE (or tail cams, e. g. I6 and 52) except when the respective jack is projected to needle transferring position as indicated in Fig. 6. As indicated before however, it is not alto ether necessary that the tail cams such as I6 and 52 be fixed in the cam system and carried at fixed distances from the fabric space 3. Should the tail cams not project into the slots at all times, the recesses between the jack butts II and I4 might be omitted, and in such a case the so-called tail butts I 4 would not (or at least need not) stand out as separate entities in the manner illustrated in Fig. 2, but undemarked portions of the back edges of the jack tails might serve the same purpose and in fact constitute tail butts. Wher tail butts are mentioned in the claims hereafter, such constructions are to be understood as included.

Preferably also a portion IT projects from the head portion of each jack to hold needle latches open (cf. Fig. 6), and'preferably the outer end of the portion I! from its inner edge to its outer edge, is inclined toward the operating butt II as shown at I8 in Fig. 2. These inclines at I8 provide cams or wedges for opening adjacent latches of the corresponding needles I at appropriate times when there are no yarn loops on the needles to open the latches. Speaking generally however these are matters of preference only.

Also speaking generally the relations of each two opposing needle jacks to their needle and to each other are substantially conventional and as customary heretofore in links-and-links machines as will be appreciated from Fig. 6 Also it will be understood from what has been said racemes t :before that the "structurerand racesnjof the"; :cam 'system'illustrated in Fig; 1: are: to be regardedzas "representativeyand the invention not limitedixto fit except,'preferentially, at the needle transferwhether or not the cam system is composedcof the particular number and shapesof blocks illustrated in Fig. 1, etc.

" However, in the cam system illustrated-the f6 tozairportion 44 where; their upper iacksaaregprojected so farthat the, adjacent hooks: of, needles J beingacarriedby lower jacks, passing, upward to rand-"over the transfer :cam 4|, are .thrust underring' stations. It is: immaterial: too. of course .1 :Jneaththe. upper jacks toua point where these hooks pass above theprojections II) of the upper ja'cksand' accordingly: are grasped by the upper :ja'cks: the relative positions are shown'in Fig. 6. .wAt 40 .thexjacks are projected extra far, as I call ,jacks arebrought. (by their operating butts. H) 10 it. 5T0: enable theneedle' hooks. to pass underto their most retracted positions at 125 and 26: by the stitch cams 21 and 28, and in comingitothese positions their needles cast off previously. drawn .loopsrof; course. .From 25 and ZBYtheJcams'lare neaththe. projections Illv of theupper or receiving lzjackazxthe headportions of the corresponding jacks must be raised of course, or allowed to rise. ltgis suificientto simply allow them to rise under :projected to rest-positions.29'anda30;.and:if'.de-; 15 the. thrustof the entering. needles. To permit :sird .the' 'jacks' of: one or bothbeds may thereqafterrbe projected as at- 3|: and immediately: re-

tracted again .to :permit the yarns and loops-to :--readju'st themselves,- i.' e.: tensions to J qualize,

' this: displacementeofv the head and mid-portions of the'upper jacks, the upper race-forming membenadjacentthe jack heads, is recessed throughout that length. of-it which passes over .a jack "before being subjected to further. action. In theawhile. the -jackris rising tov admit .a needle .and

-present instance in eachsection: the cam-."race for theoperatingbutts H has a portion 337-01? 34 #whereby the jacks may be carried completely through the section'ora feed in retractedposi- .ri falling again; i. e. is cut outfor about the length :oftherace represented by the bracket 45, and :ina manner generally similar to. the cutout 46 nfFig: 4. Preferably this cutout at 45 is made tions inwhich any needles that may beheld-.by; ras short as possible so that as soon as the upper the respective jacks. are'entirely'out'of operation and merely hold any loops that may been them;

theseidle raceportions 33 l and 34 are; simply topermit theformation-of certain types of fabrics or sti ches. In either forming stitches orv transayh m slbts,

ferring however the butts H proceed from- 29 =or 39 (or.from3l) to. race portions 35rand 36 where (because of the needle-extension l1 and their head inclines l8) a jack in the upper race jackcan be rocked, back fully into its slot again, .athei'race-forming member or members will again .be-close to therouteredgeof the. slot walls to -confineiacks. and any" needles they. may holdto Just beyond the transfer cam 41 the lower race inclines'at 41 .to retract the; jacks ..--.which;.have transferred their needles to the level refs-the racexportion- 39,:aswil1vbe observedifrom "Fig; 1. Before this retraction'ofta lower 'J'ack porti n 36 s v s t Opener assures t op ing f .thatxhaspdelivered' a needle to an upper jack 'is an upper latch of a needle held by a jack-in the lower race portion 35 or vice versa, if. thereis 'no' yarn loop in the particular hook atthe moment, or if a loop has failed to open the latch begunrhowever, the lower jack must be detached .'.from;ithe .needle, and it must be held detached .until"therneedleszand jack have reached, such relative positions. that they cannot engage again.

"of its hook; i; e. in these race portions the wedge m t t [lower rac f r in member,

end I B-of a jack not carrying a needle 'is forced between the adjacent latch and hook of its needle "(which for the moment is being carriedby. the 1" respectively opposing jack) and thus forces the ajacentithe head portions of the lower jacks, is ;-recessed :or cut: out as at 48,1 and the tail cam "IGS-is vprovided, extending. into the slots of the lower needle bed 2,. and lengthwise extending over c p if it'is not p already- Gate 5545 substantially the same'length of the cam system 1137 and 38 direct the jack butts II to 35: or 36t;in lieu;of 33'or 34, or vice versa; these maybe adjusted as indicated by the arrows on them, to

direct some or all of the jack butts of. their :aszthetcutout' 48, to engage'the tail butts l4 of .the jacks'fthat have been projected to the trans- .sferring position and thereby rock those lacks to needle-releasing positions, Fig. 6, and'hold them respective races into eitherof the two adjacentitSO rocked untiltheir butts 1 have passed sufficiently ,race'portions. Beyond 35 is a transfer point for utransferringneedles from the lower. bed I to the upperbed 2.

:In order. that needles may be transferredrup far down the incline 41 to place the projections #lfl' ofz the respective jackszbelow their adjacent .needle.hdoks. The cutout 48 :isof an appropriate "length and shape torpermit. this rocking: of the r: or retained in the lower bed as desired, the race=fi551 as Wm be .understood from Figs; 1

bf the lower cam cylinder is divided into two parallel race portions 39 and 49 at this point, separated by a transfer cam- 4|. The gate-cam v. Min-the present instance, movable as:indicate d,

and 4.

'1 The lower jack :is returnedbyz-incline 4'! to the xraceslevel 39,:and angularly immediately behind :thisrpointthe uppercam race may be provided :serves to direct butts H of the jacks 8 of the lower 2.50 axneedlettmnsferringapparatus, e. a

' needle bed 1 into either 39 or Mlat'will. How- 1 ever other means can be used for directing the lower jacks into either 39 or 40, and either selectitively... or .en. masse as. it werenaswill be underrstoodifrom' prior: practices. .Such; jacksIasLare directed to -the race portion 39 retain any loops nthey maybe carrying and proceed With? them toward the yarn guide which feeds'yarn to the -;hooks at-a later. stage as describedhereafter.

- transfer cam 59, a' cutout 5! in the upper racei'rforming memberscorresponding generally to. the cutout 48; a tail cal-n52 likethe tail cam lt, a

-, "gate "cam"53 generally-like the'gate cam 42 to "directthe-cperating butts H of the upper jacks .intoeither the race portion 54, say corresponding generally to 39, and a further projected-race portion,55'- corresponding generally to 49, and also You the other hand lower jacks that; pass; overmm the raceJ-formingmembers ofthe lower cam dy the transfer cam 4|, i. e: travel- 40, transfertany needlesthey may be carrying to their. respecttively opposing jacks. in the upper needle: bed. .To Lzbringabout this action, the operatipgbutts ,l lrzof linder provided with the, cutout. 46. before mentioned topermitthe lowerjacks .to be rocked. to ;,.admit-.needles coming down. tolthem. from the ;.upper.,. needle; bed. J" Such: an-. arrangement per- .the :,upper, "j acks ,pass. from-their; ra e portiom 36 r twtmits;gneedlesttdzbe? transferred-from Zthe IJ-ll p-er 7 to the lower needle bed as directed by the gate 53 or whatever may be used in its place.

From the race portion 39 and 54 the lower and upper jacks are retracted to the levels 55 and 56 respectively. Needles in the lower bed pass through clearing position as their jacks are car ried to the race portion 39 (or 40), and likewise needles in the upper needle bed pass through clearing position as their jacks pass toward the race portion 44. At the 39 and 44 levels therefore the previously drawn loops are at mid-portions of the needles as will be apparent from Fig. 6. At the 55 and 56 levels all the needles, whether carried by upper jacks or lower jacks, stand at the proper levels to receive yarn fed through the eye 51, the yarn actually reaching any needle at about the position 58, say. The yarns may be delivered by the yarn eye or guide either, say, into the needle hooks or onto the open latches of the needles. As the upper and lower jacks next are retracted further by the stitch cams 2i and 28, the various needles form new loops of course, each to one side or the other of the fabric depending on Whether the particular needle is carried by an upper jack or a lower jack, as will be understood from prior practices.

At 59 a latch plate serves to hold open the latches of the needles approaching the yarn at 58, i. e. regardless of whether the latch is an upper latch or a lower latch, the needle being in a lower jack or an upper jack.

The trailing side of any of the cutouts 45, 4B, 4B and 5! may be shaped to engage the jacks to rock them back into their initial positions in their slots at the proper moments, or other means may be provided to return rocked jacks to their initial positions so far as this may be necessary. Preferably however the advance sides and midpo-rtions of the cutouts 45, 46, 48 and 5| are so shaped that at every place they only just substantially permit the rise required of the jack heads under the actions of the needles thrusting beneath them (at 45 and 46) or under the action of the tail cams l6 and 52 (at the cutouts 48 and 5!), and the trailing sides of the cutouts either rock the jacks back to their initial positions as soon as that is possible, or follow closely the jack heads as they are rocked back by other means. With such shaping of the cutouts the jacks (and thereby the needles) are confined closely to their slots at. all times.

Fig. 7 illustrates one of the possible modifications of the structures so far described. Namely, one rendering the cutouts 48 and 5| unnecessary. To this end, each jack 8 is provided, at its outeredge, with a recess 60 deep enough to permit its head to rise away from a needle hook without recesses in the cam members, but, preferably, leaving an edge portion 6| to be engaged by the cam members when the respective jack is in all positions except that of transferring. Between the recesses 60 and the edge portions 6 I, the edge portion 62 may be inclined inwardly as shown in Fig. 7, so that on the retraction of the jack by a cam incline 41 or a corresponding incline in the upper race, this incline at 62, riding on the cam member, causes the jack to be rocked back to its initial position.

The operations of the mechanisms illustrated have been described in connection with the constructions and need not be repeated.

It will be observed that my invention provides large cam surfaces for raising the ack heads from their needles, namely. the extended surfaces at such tail cams as [6 and 52, with the result that'the wear is relatively slow. Further, the

arrangement is such that the race-forming members of the cam system completely confine (or at least can be arranged to confine) the jacks to their slots in such a manner that every needle is held confined to one or the other of its slots by at least one of its jacks at every moment.

As indicated before, my invention is not to be understood as limited to the details of construction and operation shown in the drawings and described above, except as appears hereafter in the claims.

I claim:

1. In a knitting machine the combination with two needle beds having a fabric space between them, a plurality of needles transferable from one bed to the other, needle jacks in one of said beds and earns to move needle jacks of the machine to needle-transferring positions, of needle jacks in the other of said beds that are recessed at the backs of their tail portions to permit rocking of those jacks to release needles, and a cam movable, relative to the latter jacks, transversely thereof, to engage successively the tail portions of such of the latter jacks as are moved to needletransferring position to thereby rock the same to release their needles and hold them rocked until there has been such jack retraction that the rocked jacks can be restored to their unrocked positions without reengaging the needle hooks.

2. The subject matter of claim 1, characterized by the fact that said cam is fixed in position in the cam system of the machine and said recessed jacks are provided with butts that are brought to the path of said cam as those jacks are moved to needle-transferring positions.

3. In a knitting machine, the combination with two needle beds having a fabric space between them, a plurality of needles transferable from one bed to the other, needle jacks having butts in each of said beds, and members providing a cam race for the butts of the needle jacks in each of the beds and extending along the needle beds close to said jacks to confine the jacks in the beds, characterized by the fact that needle jacks of atleast one of said beds are provided with recesses at the backs of their tail portions to permit them to rock to release their needles and at their tail portions are provided with outwardly projecting butts, a cam, fixed in position with respect to said race-providing members, is disposed to engage said tail butts to depress the tails to rock jacks when the respective jacks are projected to their needle-transferring positions and hold them rocked until there has been such jack retraction that the rocked jacks can be restored to their unrocked positions without engaging the hooks of their needles, and the portion of said race-forming members adjacent the heads of the recessed jacks being recessed to re- :ceive the head portions of jacks rocked by said cam.

4. In a knitting machine, the combination with two needle beds having a fabric space between them, a plurality of needles transferable from one bed to the other, needle jacks having butts in each of said beds, and members providing a cam race for the butts of the needle jacks in each of the beds and extending along the needle beds close to said jacks to confine the jacks in the beds, characterized by the fact that needle jacks of at least one of said beds are provided with recesses at the backs of theirtail portions to permit them to rock to release their needles and at their tail portions are provided with outwardly projecting butts, a cam, fixed in position with respect to said race-providing members, is disposed to engage said tail butts to depress the tails to rock jacks when the respective jacks are projected to their needle-transferring positions and hold them rocked until there has been such jack retraction that the rocked jacks can be restored to their unrocked positions without engaging the hooks of their needles, and the head portions of said recessed jacks being provided with recesses at their outer edges to permit said head portions to be rocked when projected to needle-transferring positions, said recesses having inclines to rock the jacks back to their initial positions as the jacks are retracted.

5. In a knitting machine, two coaxial needle cylinders having a fabric space between them, a plurality of slidable double-ended needles transferable from one cylinder to the other, needle jacks in each of said beds, said jacks having outwardly projecting butts at their mid-portions and at their tail portions and being recessed at the backs of their tail portions to permit the jacks to be rocked to release their needles, members encircling said cylinders close to the J'acks therein to confine the jacks in the cylinders and prividing races for the mid-portion butts of the two sets of said jacks, the race for each set including a portion retracting the respective jacks to a cast-off position, a portion projecting the jacks at least toward clearing position, a portion holding the jacks in projected positions and a 10 portion paralleling the last mentioned portion projecting the respective jacks to and retracting jacks from needle-transferring positions, cams to direct jacks to one or to the other of the last mentioned two race portions at will and a cam for the tail butts of each of said two sets of jacks and at a fixed distance from said fabric space, said cams occupying substantially the same angular positions as at least a part of the last mentioned jack-retracting portions of said races and engaging said tail butts when the jacks are at said jack-retracting race portions, the portion of said encircling and race-providing members adjacent the head portions of each of said two sets of jacks being recessed to receive the heads of rocked jacks at substantially the same angular position as the respectively adjacent tail-butt cam.

CHARLES F. MILLER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,940,520 Zimic Dec. 19, 1933 2,165,464 Eichner July 11, 1939 2,170,078 Houseman Aug. 22, 1939 2,252,769 Houseman Aug. 19, 1941 2,327,398 Bromley et a1 Aug. 24, 1943 2,381,370 Scrantom Aug. 7, 1945

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