US2644488A

US2644488A - Shedding mechanism for looms

Info

Publication number: US2644488A
Application number: US49469A
Authority: US
Inventors: Pfarrwaller Erwin
Original assignee: Sulzer AG
Current assignee: Sulzer AG
Priority date: 1947-09-20
Filing date: 1948-09-16
Publication date: 1953-07-07
Anticipated expiration: 1970-07-07

Description

ly 1953 E. PFARRWALLER SHEDDING MECHANISM FOR LOOMS 5 Sheets-Shet 1 Filed Sept. 16, 1948 IN V EN TOR. fen 0v 1 5416? WAZA ER.

A T TOP/V5 Y.

July 7, 1953 E. PFARRWALLER 2,644,488

SHEDDING MECHANISM FOR LOOMS Filed Sept. 16, 1948 5 Sheets-Sheet 2 F: C A. 5/ 87 80 79 JNVENTOR. fem/v ZAPEW/M 1 54''! July. 1953 E. PFARRWALLE-R 2,644,488

SHEDDING MECHANISM FOR LOOMS Filed Sept. 16, 1948 5 Sheets-Sheet 5 July 7, 1953 E. PFARhWALLER 2,644,488

SHEDDING MECHANISM FOR LOOMS Filed Sept. 16, 1948 5 Sheets-Sheet 4' INVENTOR. [em/v PFAEfiW/MLE/F.

ATTORNEY- July 7, 1953 E. PFARRWALLER SHEDDING MECHANISM FOR LOOMS 5 Sheets-Sheet 5 Filed Sept. 16, 1948 INVENTOR. 5PM flfimee/rnz4sz.

Patented July 7, 1953 uNiTEDfsrATEs r 2,644,488 SHEDDING MECHANISM LEO-It LOOMS Erwin Pfarrwaller, Winterth-ur, Switzerland, as-

signor to Sulzer-Freres, Societe Anonyme', Winterthun. Switzerland, a corporation. of: Switzerland Y Applicatiim Septemlier. 16,1948, Serial No. 49,469

In Switzerland September 20; 1947 cries-6s). 4'

- are claims.

The present invention relatesfto a shedding mechanism or dobby which' positively operatesthe heddles or harnesses looms for weaving,

i. e. raises them as well-as depresses them.

A n obj ect of theinvention is the provisionof a shedding-mechanism in which the heald framesare actuated by an operating} lever which 'ispositivel y' oscillated two-opposite directions,- one for raising" 'a-nd -nefor depressing the heald frames, by an oscillating'ca-m.= The. latter isos cillated b'y a reciprocating movementof two actuati-ng members piveted' thereto. The reciprocating movement is imparted to said members byactuating bars which are continuously recipr'o-- cated and temporarily individually connected to said members when actuation thereof is desired. An object of the'i'nventicnis the provision of a mechanism for bringing about-engagement and disengagement oftheactuating bars with-the actuating members at predetermined operati-ng conditions of'the'l'oom and in dependence on a pattern card. Themechanismco'mprises a two-arm switching lever and link members individually pivoted to :onearmof said lever and to always one of the actuating members. The switching lever-has two-predeterminedoperating positions and is switched from-one position to the other and vice-versa' by a control rod which is recipro catingly moved by continuously reciprocatingly moving: draw bars which engage and actuatesaid rod at desired periods of 100m operation. The

rod is swung toandout of engagement with a-lways one ofsaid drawbars by-a' lever'means the position of which is controlled by' a pattern card feeler-d'epen ding from the lever means. *A further object ofthe invention is the provisionof means for displacing the fulcrum of the lever means for positioning the control rod simultaneously'with the actuation of lifter means forl'i'fting the cardfeeler dependingfrom said lever means, from thepa'ttern card. 1

1 An object of the invention is the provision of interdependent andfsuitably-timed drive means for. positively reciprocating the actuating barsforthe cam actuating members, for positively reciprocating thedraw bars for the control rod actuatingthe switching lever, for positively reciprocating'the card.fee1er.- lifter; and the-shaft supporting theleverv means for" positioning the control rod, and for advancinga drum support.- ing the pattern card. I v

Further. andiother objects, of the present invention willv be hereinafter set forth in the accomwhat I now consider to be preferred embodiments of the invention. a Q

In the drawings: Fig.1 shows, diagrammatically and in sidezelee vation, a. section through a dobby according to.

the invention, with a sidewall removed;

- Fig.2'is a diagrammatic sectional side view of ajiportion of the. dobby according to the inven 51011;. v: V

Figs-'3' and 4' are diagrammatictop'views of the dobby according to the invention with. the driving members-for the individual harness levers and otheriparts of themechanism omitted Fig. 5 is a diagrammatic side view of a mechanism according to- "the invention for actuating the pattern card drum and the lifters for the card feelers I Fig. 6 isa-front view of the mechanism shown in Fig. 5; V

Figs. 7 to 13 are diagrammatic sectional side views of the mechanism for operating theharness levers, in different operating positions;

Fig. 14 is alarge scale illustration of a detail ofthemechanism according to the invention;

Fig. 15 illustrates. diagrammatically, an alternative arrangement for arresting: the cam disc of the mechanism. according to the invention;

Fig. 16 illustrates a detail of the mechanism according to the-invention on larger scale;

Figs. 17 and 18. illustrate thewormgearing 8| and 82 on a larger scale.

Like parts are designated by like: numerals in:

all figures of the drawings.

Referring more particularly to Figs. 1 to 4 of the drawings; numerals I and 2 designate the side walls ofthe containerof the dobby which walls support the-'dobby' mechanism; Harness operating lever 3 is supported by' shaft 4 which forms the fulcrum for the lever, the latter being" provided'with two rollers or

cam followers

5 and 6 running on cam i. This portion of'themecha nism" as well'as the means connecting lever trend the harness frames i's as shown in the patent of- Albert Moessing'e'r, No.' 2,592,820'1of April 15,..19'52. Character of movement of the harness frames depends on the configuration of. cam l. The: movement is positive. up as well. as. down, be-

cause of the provision. of two. cam followers 5;

and. 6,, each being in engagement with its own portion of 0am I. Tworecesse'sare provided on the cam for temporarily arresting the harness in its extreme positions. The-recesses x-are'so posipan ing specification. and claims and shown in the.- drawings, which by way ofillustrationshow tioned that when one roller, 6 in Fig. 1, is ina recess, the other roller; 5 in-Fig 1,-is on apro tuberance of cam 1 whereby any play of lever 3 is prevented.

Instead of providing recesses in cam I cooperating with followers and 6, recesses y as shown in Fig. may be arranged which cooperate with a follower roller I25 on an angle lever I26 whereby a spring I21 assures engagement of roller I25 with cam 'I. Lever I26 is swingably supported on the dobby frame.

Cam I is supported by shaft 8 forming a stationary fulcrum. Cam I has two actuating or hook members 9 and I0 swingably connected therewith. Link members II and I2 individually movably connect members 9 and III with the end of one arm of switching lever I3 which is swingable on shaft or swing axis I4, which forms a stationary fulcrum, a motion control rod I5 being pivoted to the other arm of lever I3. Members II and I2 and the switching lever I3 constitute what I call the switching mechanism. Lever I3 is held in its rest positions by a latch I6 mounted on shaft I9 and having two notches II and I8 adapted to engage one end of the lever against which the latch is pulled by a spring connecting a stationary part of the (lobby mechanism frame and the latch l6.

One arm of a positioning lever 22 which lever has the shape of a bell crank lever and swings about a shaft 23 is hooked in a slot 2| inthe upper end of control rod I5. The upper, horizontal, arm of lever 22 carries a weight 24 as shown in Fig. l, or is pulled counterclockwise by a spring 24' as shown in Fig. 9. A pattern card feeler 25 hangs on the horizontal arm of lever 22, which can be seen better in Fig. 6. The feelers 25 extend through and are guided by apertures in

plates

26 and 26. Control rod I5, lever 22, and the feeler 25 constitute what I term the control mechanism.

I Each harness has its own switching and control mechanism, as described above, which mechanisms are placed between the side walls I and 2 of the casing containing the dobby.

Actuating bars 30 and 3| are disposed symmetrically with respect to an imaginary plane extending through the axes of shafts 8 and I4 forming the swing axes for the actuating means 9 and the second actuating means I3, respectively, and it is sufficient-to explain the function of the upper bar 30 only. Its ends are rigidly connected with one end of

horizontal rods

32 and 33 which extend at a right angle to bar 38. The

rods

32 and 33 are provided at their other ends with

pins

34, 35 and 36, 37, respectively, to which links 38, 39 and 40, 4| are pivoted, respectively.

Links

38 and 40 swing about shaft I4 and links 39 and 4| about shaft 8. This limits movement of bar 30 parallel to its longitudinal axis on an imaginary cylinder surface or an arcuate path 27. Likewise, bar 3| moves on the surface 28 of an imaginary cylinder.

The

pins

35 and 31 of

rods

32 and 33, respectively, are connected by connecting

rods

43 and 44" to

cranks

45 and 46 of a shaft 47 and are reciprocatingly moved 'to and from their end positions I06, I08 and I01, I09 on the arcs 21 and 28. Shaft 41 is connected to and operated by the loom drive by means of a chain 48 and a sprocket wheel.

Spur gear wheels

49 and 50 drive crank shaft 5| which operates the actuating bar 3|, Fig. 2. The

bars

30 and 3| perform what I call translatory movements whereby all points of the bars travel along parallel paths of equal length which are not necessarily straight. The axis of members 8, I4, I06, and H9, and 8,

I4, I01, and I20 are at the corners of parallelograms in the device according to the invention. See Fig. 1.

The draw bars and 56 are guided in slots 5'1 and 58 of the

guide members

59 and 60 which are fixed to the walls I and 2. The ends of the draw bars 55 and 56 are provided with pins GI and 62, respectively, which extend individually into slots of one end of two

arm levers

63 and 64 and 63' and 64', Figs. 2 and 4. The two arm levers are supported by a shaft 65 and have at their

ends cam followers

66 and 61, and 66 and 61, respectively, which engage the

cams

68 and 69, and 68 and 69 Tension springs 10, Fig. 2, assure engagement of the cam followers and cams.

The

cams

68, 69, 68, 69' are so formed that the draw bars 55 and 56 are always moved in opposite directions in their

guides

51 and 58. During one revolution of cam shaft II

bars

55 and 56 move once up and once down. Shaft II is driven by crank shaft 41 through spur gear wheels 49, I2 and 13.

Control rod I5 extends between the draw bars 55 and 56 and has recesses at its sides which are adapted to receive the draw bars. The length of the recesses 01. between their end abutments I30 and I3I, Fig. 14, is greater than the height of a

draw bar

55 or 56 plus b of the stroke of said bars. This permits idling of the bars in

slots

57, 58 for the purposes which will be explained later. The depth d of a recess plus the width e of rod l5 between the recesses is smaller than the distance J between the

bars

55 and 56 to assure that always one only of the draw bars engages the control rod I5 for lifting or depressing it. The sum of the depth d of the recesses plus the width e of rod I5 between the recesses is greater than the distance 1 between the draw bars 55 and 56 to always assure engagement of a recess by a draw bar. For proper operation of the mechanism the following equations must be fulfilled:

Shaft 83 of the pattern card drum 11, Fig. 1, is driven by shaft II through the bevel gear wheels I8, I9, the shaft 80, Fig. 4, a worm 8| on the shaft and the'worm wheel 82 which is rigidly connected with shaft 83, Figs. 4 to 6. Whenever worm 8| makes one complete revolution, during a determined angle, Fig. 19, wheel 82 is rotated through an angle t, Fig. 1, the extent of which depends on the configuration of the cam I35 on member 8|. The worm gearing 8| and 82 is shown in detail in Figs. 16 to 18. During the part of revolution of shaft 80 when worm 8| does not move wheel 82, thepattern card drum I1 stands still. During the period the drum is rotated through angle t, the feeler 25 is lifted out of pattern card T! by a lifter 86.

As seen in Fig. 3, the lifter 85 is connected to one end of two-

arm levers

97, 98 swinging about shaft 99. The other ends of said two-arm levers are pivoted to link members and 96, Figs. 5 and 6, which are also pivoted to elbow levers 93 and 94, respectively, on shaft 90. The latter is revolvably borne in side walls I and 2 and has a crank 89 atone end which crank carries a cam follower 88 which follows a groove in drum 8'! fixed to shaft 80. To levers 93 and 94 further link members I00 and |0| are pivoted which actuate the short two-arm levers I02 and I03 which also swing on shaft 99.

' As shown inFig. 3, the short two-arm levers I02; vIflt'carry; the. shaft 23 which supports the positioning levers, 22. If shaft 23- would be immovable; lever 22 would be bent upon lifting of the feelers 25 because the device is so constructed that control rod I5 engages, draw bar to when the respective feeler rests on card IT, Fig. 9. To. prevent bending. of member 22 its fulcrum is lifted by levers me, its whenever lifter 86 is moved toposition 85.

#LifterxSfizand shaft 23, forming the fulcrum of lever 22; aresimultaneously moved up and down by cam 81. .When roller 88,- which follows cam. 8"I:,.is moved to the right in Fig. 5, bellcrank lever 8-9.,.93 turns counter clockwise, pulling linksv I and 95 downand turning levers QIand I02 clockwise. -This causes upward movement of lifter 86 as; wellas of fulcrum 2.3. lifter.- 86 causesv lifting of feelers25 out of their holes in-the pattern card TI and clockwise movementof. levers 22 about fulcrum 23 and movement of. controlrod I from its right position (Fig. 1) to its left, position (Fi 9). Clockwise movement of be'llcrank lever 89, counter-clockwise movement of leversill and I02 and downward movement of lifter B16 and fulcrum 23*. If a. feeler 25.1 is, above a hole in the pattern cardat thismoment, the horizontal arm of lever 22,: supporting said. feeler follows the downward.

movement-tor lifter- 86, because of weight 24 or spring 2.4., and lever-22 turns counter-clockwise about fulcrum 23,v moving rod I5 from its left to itsrightposition. If; there is no hole below feeler 25, the horizontal arm of its lever 22 cannot follow thedownwardmovement of lifter 86 and the lever remains in the, position in which rod I5 is in its left, position. I

The mechanism operates as follows: The'card drum] I makes; an angular movement t; corresponding to one section of pattern card 'terpositions and then back tofcentral position.

During this movement of draw bars 55,, 55 the actuating bars 39, 3| are either in their dead center positions. I06, I01 or I08, I09. Fig-., 3;, revolves twice as fast as crank shaftc'l.

The dobby according to the inventionoperates according to. the following rule: No hole in card-.11" will be followed by a depressed heald frame; hole is followed by a raised heald frame, orv-iceversa, according to the type of connection of lever 3. with the'heald frame. In the mechanism according to the invention illustrated in Figures land '7 to 13 no hole in the pattern card causes clockwise movement of lever 3' and Upward. movement of- 93 causes Shaft 80,

of bar 3| to the right, arrow III, bar 3I sliding I moves down and causes disengagement of .member Qfrom bar through switch lever I3 and link I I, as seen in Fig. 7. During the movement hole on the pattern card, has not changed its position. I.

If; the heald frame is to retain its up position. there must again be a hole in the pattern card so that rod I5 is again pressed to-the right for"en-' gagement with bar 55 which will make an up stroke that does not move rod l5 which is already in the up. position,. Fig. 8, as the length of: the recesses in rod ii: are greater than the heightof bars. 55, 56. If then bars 30 and 3| return to positions I56, lfil, bar 36 glides along guidesur:

face portion. I it of member 9 and swings it up in the direction of arrow H4 to the position shown If theharness must retain the raised.

in Fig. 7. position, the following stroke down of bar 55. does not affect the, position ofthe harness, as rod I5is in its lower; position.

The following is a description of what happens:- when the heald frame is to be moved-from the.

raised to the depressed position and stays therein.

From the position shown, in Fig. 1, lever-3 must be moved clockwise for depressing the. heald frame connected therewith, and there must be. no hole in thepattern card when it is advanced for preparing this movement. Rod I5 is then depressed heald, and hole causes counterclockwise movement of 1ever3 and raised heald. When the; shed is changed either member 9 or ID is in engagement with bars 35; or 3-I What happens when the harness is and stays in theraised position will, be described first. In the positionshown in Fig, 1, finger or feeler 25 is .inserted inahole of the pattern card and lever 3- is=in;its left position during the following pick,

1. e; lever 3 will stay in the position shown in Fig. 1. Rod I5. is pushed tothekright by lever 22. and to engagement withbar 55.. The. latter.

moved to the left and bar 58 can move upwardly without affecting members 9 and IIlwhich are in the position illustrated in Fig. 1.. Due to the,

movement of bars 38, (H to the right the system.

the-position shown in Fig. 10 whereby member 9 is swung up and out of engagement with bar 30. which is in the position Hi8. At the return of bars 3t, 3.! to: positions I06, I01, bar-3I pushes member it .down by sliding on its guidesurface portion IIii whereby the system is switched to the position. according to Fig. 11. I

, If,;.after the pattern'card has made a further angular movement t, there is again no hole in. card 1? members 9 and I0 will not alter their positionsas bar 5&- can make an idle stroke up.

Atthe movement of bar 35 to the right itswings: member 9 up by sliding along its guide surface portion I I5. whereby the position shown in Fig; 1( is reproduced. 1 V

For a-change from depressed harness-position corresponding. to Fig. 11 to: raised position,. i. e for :moving: lever 3 over to the left, a hole in the; pattern .card must be presented to feeler 25 whereby rod I5 is moved to engagement with bar 55 and pushed down by it and the condition of the deviceshown in Fig. 12 is 'produced- Now,

bar 3! will move member It to the right whereby J cam? and' with it lever 3 is moved counterclockwise to the position of Fig..13;

7 If. from the position shown in Fig 13 thetnextposition of the harness shall be the depressed one, no hole must be in the pattern card so that lever 3 will be moved clockwise. Then rod [5 is swung to the left and bar 56 can make an idle stroke down whereby member it remains engaged with bar 3| and the apparatus is brought to the condition shown in Fig, 12 when

bars

30, 3| have been moved to the left. The harness is thereby moved into the depressed position.

If, however, from the position of Fig. 12 no change of the heald frame must occur, there must again be no hole in the pattern card.

If there is a hole in the pattern card at the motion after the condition according to Fig. 13, no change of the shed will take place. Rod l5 is then in position where it engages bar 55 and will-be lifted thereby whereafter the system is in the condition according to Fig. 8. Bars and 3|, can idle to the left and the system assumes the condition shown in Fi 7.

- The dobby can operate forward as well as backwards. This is of advantage if in case of a failure already inserted weft threads must be removed. In this case the dobby is operated in reverse, at first into the last previous picking position and then pick by pick till the faulty pick is reached.

Fig. 1'7 shows the worm 8| as in Fig. 3 but in a greater scale. The shaft 80 makes one revolution during one picking cycle and rotates the worm wheel stepwise by the pitch 1? of the pattern card drum 1'! (Fig. 1) in the following manner. The drum 11 can only be rotated when the feelers 25 are lifted out of the pattern, therefore the ends I34 and worm tooth I35 (Fig. 17) are lying within the centri-angles a. and ,8 (Fig. 18) in two parallel planes in a right angle to the shaft 89. Thus during the rotation of the shaft 80 within the angles a and ,8, there is no rotation of the worm wheel 82; rotation of the worm wheel is caused by the passover part 133 of the worm tooth I35 which extends within the angle '7, Fig. 16.

While I believe the above described embodiments of my invention to be preferred embodiments, I wish it to be understood that I do not desire to be limited to the exact details 'of method, design and construction shown and described, for obvious modifications will occur to a person skilled in the art.

I claim:

I l. A dobby for positive actuation of the shedding mechanism in looms for weaving, comprising a harness operating member, a cam engaging said member, two actuatin members individually pivoted to said cam for actuating it, and two positively driven actuating bars individually engageable with said actuating members and actuating same when in engagement therewith.

- 2. A dobby as defined in claim 1 in which said operating member is provided with two cam followers for engagement with said cam.

' 3. A dobby for positive actuation of the shedding mechanism in looms for weaving, comprising a harness operating member, a cam swingable about an axis disposed within and at a right angle to said cam, two actuating members individually pivoted to said cam for swinging it about its axis, two positively driven actuating bars individually engageable with said actuating members and actuating same when in engagement therewith, a switching lever swingable about an axis extending at right anl32 of the 8 gle thereto, two link members individually swingably connected with one end of said switching lever and pivoted, individually, to'

said actuating members and placing same for engagement or disengagement with said actuating bars depending on the position of said switching lever; the swing axes of said switching lever and of said cam, and the pivot on said switching lever of one of said link members when placing same for engagement of one of said actuating members with one of said actuating bars being in one plane.

'1. A dobby as set forth in claim 3, comprising two more link members, each of said last mentioned link members having one end swingable about the axis of said switching lever and having another end swingably connected with one of said bars, the individual distances of the swing axes at one end of said link members from the respective swing and pivot centers of their other ends and the distances of the pivot centers of said actuating members on said cam from the swing axis of the latter being all alike.

5. A dobby for positive actuation of the shedding mechanism in looms for weaving, comprising a harness operating member, a cam engaging said member, two actuating members individually pivoted to said cam for actuating it and individually having guide surface portions, and two positively driven actuating bars individually engaging said guide surface portions for placing said members in desired operating positions.

6. A positively actuated shedding mechanism in looms for weaving, comprising a harness operating member swingable about a fulcrum and having two cam follower rollers connected therewith, a cam swingable about a fulcrum and having a surface portion engaging said rollers, said surface portion having two recesses individually accommodating said rollers when said operating member is in an extreme operating position for temporarily arresting the mechanism, two actuating members individually pivoted to said cam for actuating it, and two positively driven actuating bars individually engageable with said actuating members and actuating same when in engagement therewith.

7. A dobby for positive actuation of the shedding mechanism in looms for weaving, comprising a harness operating member, a cam swingable about a fulcrum, two actuating members individually pivoted to said cam for swinging it about its fulcrum, two positively driven actuating bars individually engageable with said actuating members for actuating same when in engagement therewith, a positively oscillated switching lever, two link members individually pivoted to one end of said switching lever and to said actuating members and placing same for engagement and disengagement with said actuating bars depending on the position of said switching lever, and latch means slideably engaged by said switching lever for temporarily holding it in its extreme operating positions.

8. A dobby as defined in-claim '7, said switching lever having two arms, said link members being pivoted to one of said arms, said latch means having the form of a lever having two notches, the other arm of said switching lever having an. end portion formed to be inserted in one of said notches at a time, and a spring pressing said latch lever to said end portion.

ing a harness operating member, a cam swingable about a fulcrum, two actuating members individually pivoted to said cam for swinging it about its fulcrum, positively driven actuating Y bars individually engageable with said actuating members for actuating same when in engagement therewith, a switching lever, two link members individually pivoted to one end of said switching lever and to said actuating members and placing same for engagement and-disengagement with cam-actuatedmember pivoted to each of said draw bars and adapted to reciprocate said draw bars in opposite directions parallel to themselves.

10. A dobby as defined in claim 9,'said recesses having each an abutment on each end thereof for engaging one or the other side of a draw bar, the distance between said abutments of one recess being greater than the height of a draw bar plus the extent of halfof the stroke of said bar.

11. A dobby as defined in claim 9, the depth of one of said recesses plus the; thickness of said control rod between said recesses being smallerthan the distance between said draw bars.

. said actuating bars depending on the position of individually pivoted to one end of said switching lever and to said actuating members and placing same for engagement and disengagement with said actuating bars depending on the position of said switching lever, and a control rod pivoted to said switching lever and having two oppositely positioned'recesses, a draw bar disposed on either side of and at a right angle to saidcontrol rod adjacent said recesses and adapted to be temporarily engaged thereby, two levers pivoted individually to said draw bars and extending at a right angle'thereto, eachlever having a cam follower roller connected therewith, two. rotating cams individually engaging said rollers and being so formed as to actuate said levers to move said draw bars parallel to themselves and simultaneously in opposite directions from and to central position in which they are adjacent,

ing and advancing said card, a lifter abutting I said positioning lever and adapted to lift it for lifting said feeler out of an aperture in the pattern card, and drive means common to said drum and said lifter and advancing said drum after said lifter has removed said feeler from the aperture in which it was inserted. 14. A dobby asset forth in claim 9, comprising a positioninglever movably connected to said control rod and moving said rod to engagement with one or the other of said draw bars depending on the position of said positioning lever, a pattern card feeler depending from said lever, a pattern card having apertures adapted to receive said feeler, a revolvable drum supportirw and advancing said card, a lifter abutting said positioning lever and adapted to lift it for lifting said feeler out of an aperture in the pattern card. a shaft supporting said positioning lever. displaceable support means supporting said shaft, and actuating means connected with and actuating said lifter and connected with and simultaneously displacingsaid support means.

15. A dobby for positive actuation of the shedding mechanism in looms for weaving, comprising a harness operating member, a cam swingable about a fulcrum, two actuating members individually pivoted to said cam for swinging it about its fulcrum, two positively driven actuating bars individually 'engageable with said actuating members for actuating same when in engagement therewith, a switching lever, two link members 16. A dobby as set forth in claim 15, said-r0 tating cams being so formed as to move said draw bars alternately.

17. A dobby for positive actuation oithe shed: ding mechanism in looms for weaving, comprise ing a harness operating member, a cam swingable about afulcrum and engaging said member, two actuating members individually pivoted to said cam for swinging it about its fulcrum, two actuating bars individually engageable with said actuating members for actuating same when in engagement therewith, a switching lever,'two link members individually pivoted to one end of said switching lever and to said actuating members and placing same for engagement and disengagement with said. actuating bars depending onthe position of said switching lever, a control rod pivoted to said switching lever and having two oppositely positioned recesses, a draw bar disposed on either side of and at a right'angle to said control rod adjacent said recesses and adapted to be temporarily engaged thereby, two

levers pivoted individually to said draw bars at a right angle thereto, each lever having a cam fol lower roller connected therewith, two cams ine dividually engaging said rollers and being so formed as to actuate said levers to move said draw barsin' opposite directions from and to a central position, a rotating shaft supporting said cams, drive means common to said shaft and to said actuating bars and rotating the former and sub-' ating bars have reached an extreme operating position.

18.-A' dobby for positive actuation of the shedding mechanism in looms for weaving, comprising a harness operating member, a cam swingable about a fulcrum and engaging said member, two actuating members individually pivoted to said cam for swinging it about its fulcrum, two actuating bars individually engageable with said actuating members for actuating same when in engagement therewith, a switch-- ing lever, two link members individually pivoted lever and having two oppositely positioned recesses, a draw, bar disposed on'either side'of and at a right angle to said control rod adjacent said recesses and adapted to be temporarily engaged thereby, two levers pivoted individually to said draw bars at a right angle thereto, each lever having a cam follower roller connected therewith, two cams individually engaging said rollers and being so formed as to actuate said levers to move said draw bars in opposite directions from and to a central position, a positioning lever having one arm movably connected to said control rod for laterally swinging it into and out of engagement of one of its recesses with one of said draw bars, a pattern card feeler movably connected with the other arm of said positioning lever, a substantially reciprocatingly movable feeler lifter abutting said other arm for swinging said lever and its feeler out of card engagin position, a shaft displaceable parallel to itself in the direction of movement of said card feeler and swingably supporting said positioning lever, and drive means connected with said feeler lifter and said last shaft for simultaneously moving said feeler lifter and displacing said shaft.

19. A dobby for positively actuating the shedding mechanism in looms for weaving, comprising a harness operating member, actuating means engaging said member, a translatorily moving member, and a hook member having one end movably connected with said actuating means and having a hook substantially at its other end and adapted to be engaged by said translatorily moving member; both ends of said hook member performing a translatory movement conforming with that of said translatorily moving member, when the latter engages said hook member.

20. A dobby for positively actuating the shedding mechanism in looms for Weaving, cornprising a harness operating member, actuating means swingable about a stationary fulcrum and engaging said member, a translatorily moving member, a hook member having one end pivotally connected with said actuating means and having a hook substantially at its other end and adapted to be engaged by said translatorily moving member, and second actuating means swingable about a stationary fulcrum and movably connected with said hook member; said fulcrums, said hook and the pivot axis of the pivotal connection of said hook member and said first actu'-. ating means being disposed at the corners of an imaginary parallelogram at all operating positions of said mechanism when said hook is engaged by the translatorily moving member.

21. A dobby for positively actuating the shedding mechanism in looms for weaving, comprising a harness operating member, actuating means swingable about a stationary fulcrum and engaging said member, a translatorilymoving member, a hook member having one end pivotally connected with said actuating means, and having a hook substantially at its other end and adapted to be engaged by said translatorily moving member, a lever swingable about a stationary fulcrum, and a link member swingably connected with one end of said lever and With said hook member for swinging the latter in and out of engagement with said translatorily moving member depending on the position of said lever; the axes of said fulcrums and the swing axis of the connection of said link member with said lever being disposed in an imaginary plane when said hook is engaged by said translatorily moving member.

22. A dobby for positively actuating the shedding mechanism in looms for weaving, comprising a harness operating member, actuating means engaging said member and swingable about a stationary fulcrum, a member reciprocating along an arcuate path, and a hook member having one end movably connected with said actuating means and having a hook substantially at its other end and adapted to be engaged by said reciprocating member; the radius of said arcuate path being equivalent to the distance between said stationary fulcrum and the point where said hook member is swingably connected with said actuating means.

ERWIN PFARRWAILER.

Number Name Date Zollikofer Mar. 30, 1948'