US2551492A

US2551492A - Weaving loom

Info

Publication number: US2551492A
Application number: US30791A
Authority: US
Inventors: Hindle Thomas
Original assignee: Individual
Current assignee: Individual
Priority date: 1947-06-13
Filing date: 1948-06-03
Publication date: 1951-05-01
Anticipated expiration: 1968-05-01

Description

May 31, W51 T. HINDLE 295519492 WEAVING LOOM Fild June 3, 1948 14 Sheets-Sheet l By W' Em;

Atiorneys May 1, W51 T. HINDLE 2,551,492

WEAVING LOOM Filed June 3, 1948 14 Sheets-Sheet 2 $5 ;nve tor kg Q MA SW A llorney s T. HINDLE May 11, 1951 WEAVING LOOM l4 Sheets-Sheet 5 Filed June 3, 1948 r. V 9 n r O U A Inventor May '11, 1951 T. HINDLE 2,553,492

WEAVING LOOM Filed June s, 1948 14 Sheets-Sheet 4 a w W m Inventor By W k i r- Attorneys y 1951 T. HINDLE 2,551,492

WEAVING LOOM Filed June 3, 1948 14 Sheets-Sheet 5 E i Inventor By W1 Attorney;

May 1, 1951 T. HINDLE 2,551,492

WEAVING LOOM Filed Jfine s, 1948 14 Sheets-Sheet 6 W I x 4 gab 3 36 WEE Inventor Attorney:

y L 11951 T. HINDLE 2,551,492

WEAVING LOOM Filed June 3, 1948 14 Sheets-$heet 7 FIG. a;

May 1, 1951 T. HINDLE Filed Jun 5 1948 m/mn l4 Sheet 8 lllllllllllllll Attorn y 1951 T. HlNDLE 2,551,492

WEAVING LOOM il J ne 4 14 Sheets-sheet 9 d m a m v m N m w A itorney;

y 9 31951 T. HINDLE 2,551,492

WEAVING LOOM Filed June 5, 1948 14 Sheets-Sheet 10 A tlorneyr E L D m H T WEAVING LOOM Filed June 3,

l4 Sheets-Sheet 11 Attorney:

May 1, 1951 T. HINDLE 295519492 WEAVING LOOM Filed June 3, 1948 14 Sheets-Sheet 12 MM mkm Attorney:

y 1951 T. HINDLE 2,551,492

WEAVING LOOM Filed June 3, 1948 14 Sheets-Sheet l3 May A, 19531 T. HINDLE 2,551,492

WEAVING LOOM Filed June 3, 1948 Invent L WMA 5M Attorney:

Patented May 1, 1951 UNITED WEAVING LOOM Thomas Hindle, Blackburn, England Application June 3, 1948, Serial No. 30,791 In Great Britain June 13, 1947 8 Claims.

This invention relates to improvements in looms for weaving, and while the invention, either wholly or in part, may readily be applied with suitable and obvious adaptation to any kind of loom, it is particularly applicable, and will be herein described in particular reference, to heavy looms of exceptional width, such as looms for weaving papermakers felts.

In such looms, the reed-width of which ranges from about 20 feet to over 50 feet, the ordinary well-known construction of warp and shuttle protector mechanism is far from satisfactory. This known mechanism consists of a long shaft or stop-rod mounted in bearings on the slay or the slay-swords, which stop-rod is provided with a finger-lever bearing on the shuttle-box swell at each end, and also with one or more forwardly projecting blades or daggers, which latter, when the shutter fails to enter a box and open out the swell at the proper time in the slays forward movement, engage a corresponding number of abutments or frogs supported more or less resiliently on the framework and/or the breast-rail of the loom, and thus act directly to arrest the slay in its forward movement, also concurrently to stop all other moving parts of the loom.

These daggers and frogs, also the supports for the latter, are subjected to very severe impact loads which, especially in the case of heavy and wide looms, cause frequent damage to the parts involved, with resultant expense for repairs, coupled with serious loss of production.

The initial engagement of the daggers with the frogs, and the corresponding displacement of the latter (or one of them) is usually arranged to displace the starting-handle from the catch or toggle-lock which normally retains the handle in the run position, the object being to allow a loaded spring, or in some cases an elevated weight, to act to disengage the driving clutch and thereby to reduce the load imposed on the frogs, and further with the same general object, to apply a friction brake fitted to one of the revolving shafts of the loom, usually the crankshaft, or some other shaft revolving at a speed much lower than that of the electric motor employed for driving the loom.

The intended purpose of the said spring is to accelerate the starting-handle and linkage connections leading therefrom to the clutch and brake, together with the controlling parts of these latter, so as to return them as quickly as possible to their stop positions with the above stated object.

Manual operation of the starting-handle from,

the stop to the run position involves, however, not only overcoming the brake-spring pressure (which increases in some degree during such movement) but also exerting the additional pressure needed to engage the clutch. In practice, therefore, the pull of this spring is strictly limited to accord with the maximum manual effort permissible for operating the starting-handle.

For the reasons stated, therefore, the retarding action provided by the ordinary loom brake of known construction, even assuming this could be instantaneously applied, is very much less than that required to stop the moving parts of a loom with the necessary promptness ,to enable a friction-brake to replace the sprag-action of the customarydagger and frogmechanism.

In addition, moreover, to the ordinary loom brakes inadequatestopping power, there is an unduly long delay or time-lag between the daggers initial engagement with the frogs and completion of the operational sequence comprising disengagement of the clutch and full application of the brake, even when this operation is performed under the action of a loaded spring, such delay consisting of, firstly, the time taken to displace the starting handle from its catch and, secondly, the time taken by the limited spring pressure available to overcome the inertia of the relatively heavy. parts and return them to their respective stop positions.

If the brake is applied by the release of an elevated weight, instead of a loaded spring a still longer time-lag in attaining full application of the brake is unavoidable, because of the limited acceleration of the falling weight in comparison with that provided by a suitable spring.

In the known constructions, the frogs, therefore, not only absorb the momentum of the moving parts of the loom, but also oppose the driving effort of the motive power until the clutch begins to slip in the course of its disengagement, and,

' in fact, the loom slay and other parts have usually been brought to a standstill by the frogs alone by the time, if not before, the loom friction brake of known construction has been brought into action.

The driving clutch, of course, may be so arranged that it will slip if subjected to a torque somewhat in excess of that to be transmitted in order to drive the loom at its normal speed, the object being to ensure that the clutch will start to slip immediately the daggers engage the frogs. While this may ease the problem in some degree as regards the frogs and their supports, it cannot be accepted as a satisfactory solution, because a clutch, if adjusted in such manner, will be liable to slip during the development of each picking impulse, and furthermore, will require a longer time, when starting, to bring up the loom to its normal running speed.

Quite irrespective of the method to be employed for arresting their motion in the stated or similar circumstances, it is obviously beneficial to reduce to the practicable minimum the .inertia, and therefore,- the momentum, of the whole of the loom parts which have to be brought, very quickly, to a complete standstill. Heavy flywheels, for example, which in some cases are fixed.--.on-.the loom crankshaft multiply the hereinbefore described dificulties, and, therefore-:simply cannot be tolerated.

In heavy looms of exceptional width, a control rod is usually fitted along the breast-rail, and, at the driving end of the loom, is hinged to -the starting-lever which controls the action of the 'clutch;.and;brake. The purpose of .the said con- ;trol rod; is .to enable the weaver .to start and stop the loomfrom any ;position-along the'loom front,

ran-,obvious-convenience in the caseof wide looms.

whilelthis control rod-is readily operated-bye l hand for ordinary starting and stopping purpose, its :inertia,.which is .very considerable, causes, in thewase of automatic stoppingaserious increase ,underautomatic control.

lag in disengaging-the clutch intensifies the load ..on-the..frogs.and. also prolongs the period of its ..application thereon.

-Heavyandwidelooms employed for weaving paper .makers ieltsa-are almost. invariably of the i ick atawill type. with drop-boxes at both ends of the.slay. Weft-failureedueto breakage of weftcr. exhaustion of theshuttle package, unless .detected. immediately bythe weaver and appropriateaction ,taken,..resu1ts in.,serious delays-due to the,. conse ,quentunweaving and finding ofthe correctshe'd .to,enab1e Weaving to be. continued. In spite of these production delays, however, such looms have nothitherto beensatisfactorily equipped with weft-fork stop=mechanism, mainly for two reasons, .the -first being ,the difiiculty 1 presented by. the necessityof stopping. the loom automatically byreasonof weft failure with the essentialpromptness to, be of real practical .value, and

the second beingthat none of .theknown so- I called "centre weft-,fork .Jnotions satisfactorily fulfils the: requirements.

j In many known weft-fork .stop mechanisms, reliance ,is ,placed upon-gravity, in some cases .forks downward. movement.

tion, therefore, the.fork is,liable .to be held up by .thejfrictional resistance .ofa strong and dense warp while if ,weighted orprovided with a heavier spr n to ensure its proper descent through the warp, the fork would impose a greater load than the weft could satisfactorily Support, in either arrangement .the ,operation .being ,unreliable.

Furthermore, the iork,movement is usually de- ,rived from ,thatof the, slay, with .the resultthat .the, operation must be ,timedas permittedby=the motionandnot vice versaas r-i's obviously ,desirable whilein .most cases ,the. action. involves :such undesirable .dela-y @that-the slay is close .to or actually; in its .fr'ont position before displacement of the starting handle from its catch has been effected.

The main object of the invention is to provide improved means for driving, stopping and, in certain circumstances, reversing looms, especially heavy looms of exceptional width, such driving means under manual control bringing up the crankshaft and co-driven parts to their normal running speeds in a short period of time corresponding to about 60 degrees or less of the crankshafts revolution, and such stopping means, .under either manual or automatic control or both disconnecting the drive and arresting all the moving parts of the loom, including the slay, in a shorrtperiod .of time corresponding to about 30 ,degrees .or lessof the crankshafts revolution, such saidstopping means being initiated automatically by reason of either the shuttle failing .to enter the shuttle-box at the proper time or any one of a number of Weft-forks detecting the ab- .sence ofweftin the shed at or shortly before the .time when theshuttle isnormally due -to enter the box,-and such-reversing means, under manual control, enabling the slay, after it has'been so arrested in its forward movementto be returned .atwill to its back position, or thereabouts, during whichmovement the crankshaft and its co-driven parts are caused to make: a partial revolution in the reverse direction, thereby re-opening the last shedin which the faultoccurred.

,Afrn't'ner object of the-inventionis to provide ..a novel combination comprising a flywheel, a friction clutch and a friction brake, the flywheel .ancl clutchouter member being mounted on a short primary shaft which is supported in suitable bearingsand driven byan electric motor (preferably by .a flexible coupling) either at or about the same speed as that of the electric motor, whereby.thefiywheel, clutch and brake all have maximurneffectiveness for their respective, purposes. A secondary shaft, also supported insuitablebearings in axial alignment with the saidprimary shaft, has mounted on it the inner memberof .the clutch and also the inner member of the brake,.the outermember of which latter is preventedlfrom revolving, and may be part of, .orattached to, a casing provided to enclose the .fiywheel, clutch and brake. A common shipper, .slidably mounted onthe secondary shaft between .thetwosaid inner members, serves to disengage the brakeand engage the clutch, and vice versa, so that either the saidsecondaiy shaft-may be clutched to and drivenfrom the motor-driven primary shaft, thebrake being first disengaged, .or alternatively, the secondary shaft may be declutched and promptly stopped byengagement of the .brake underaction ofa loaded spring. The said flywheel, clutch and brake, due to their relatively small physical dimensions as a direct aided by. alight spring, to effect the whole of the consequence of their operation at or about the ,In such construcspeed of the electric motor, provide'an unusually compact assembly, while the manual efiort required to release the brake, against the action of the said spring, and to engage the clutch, is

, reducedto an absolute minimum in'relation to the desired stoppingpower of the brake.

In looms of the drop box type the changing movement of the shuttle-boxes is liable to be impeded by a misplaced shuttle or by a damaged picking stick 'orpicker and in order to prevent breakage of the parts, it is usual to include a safetyescapernent in the-actuation linkage of each set'of boxes, each such escapement being.selfreleasing upon overload caused by the jamming of its associated set ofboxes.

When a set of boxes jams in this manner, the picking mechanism at the same end of the loom is in turn impeded, because in such circumstances the picker cannot enter, as it normally does, one of the slots provided in the backs of the boxes. To prevent damage to the picking mechanism and associated parts it is common practice to incorporate therein some suitable form of safety escapement which will release automatically upon overload.

With the construction of loom drive hereinbefore referred to as forming an object of the present invention comprising a clutch and brake operating at or about the speed of the electric motor used to drive the loom, which clutch is disengaged and the brake applied with exceptional rapidity by means of a loaded Spring, consequent upon the tripping, by automatic means, of a secondray toggle included in the linkage connecting the loom starting-handle (or its equivalent) to the shipper lever which actuates the clutch and brake and having means whereby the secondary toggle may be tripped automatically by reason of (l) the shuttle failing to enter the box at the appropriate time in the slays forward swing, or/and (2) the absence of weft in the shed as detected at or about the time when the shuttle is due to enter the box after its flight across the loom in either of such events the slay being promptly arrested in its forward swing, it is possible to provide means, and the provision of such means form a further object of the invention whereby the moving parts of the loom will be automatically and promptly arrested in the event of either set or both sets of boxes jamming during their change movement, such stoppage of the loom being initiated when the slay is approximately in its most forward position (when the boxes are about half-way through their change movement) and thereafter completed before the loom crankshaft has revolved sufficiently further to effect commencement of the next picking operation.

The means according to the invention for achieving the aforesaid object comprise mechanical linkage connections of any convenient form between the usual box-motion safety escapement and the aforesaid secondary toggle, whereby the latter will be tripped consequent upon the automatic release of either of or both such escape ments, and all the moving parts of the loom promptly brought to rest with the slay having swung back only about one third to one half of its sweep from its most forward position.

The invention is illustrated in and will be described with reference to the accompanying drawings in which:

Fig. 1 is a longitudinal section showing the assembly of the high-speed flywheel, clutch and brake, also worm-gear box;

Fig. 2 is a cross-section of the clutch and brake assembly showing their common operating lever;

Fig. 3 is an end elevation of the brake;

Fig. 4 is a part end-elevation of a wide loom showing the driving arrangements according to the present invention;

Fig. 5 is a plan corresponding with Fig. i;

Figs. 6a, 7a, and 8a, are elevations showing the primary and secondary toggle mechanism, also the tripping mechanism, in Various positions;

Figs. 6b, 7b, and 8b are plans corresponding respectively with Figs. 6a, 7a and 8a;

Fig. 9 is a broken front elevation of the lefthand end of a loom slay showing the light stoprod fitted with dog and dagger;

Figs. 12?) and 1312 are details to illustrate the 7 spring escapement action;

Fig. 15 is a part cross-section through a loom showin the assembly of the weft-fork cam-actuated mechanism;

Fig. 16 is a timing diagram, and 7 Fig. 17 is a part cross-section through a loom showing the use of springs or weights to return the slay to its rear position;

Fig. 18 is an end elevation of a well-known arrangement of box-motion transmission levers embodying a safety-escapement;

Fig. 19 is a similar view with the box-motion transmission levers in a different position;

Fig. 20 is a similar view showing the safety escapement in action;

Fig. 21 is a plan showing the said box-motion transmission l vers and certain added parts according to the present invention;

Fig. 21a is a detail of the feeler-lever and coacting trip-bowl;

Fig. 22 is a front elevation, partly in section, showing means for the automatic displacement of the aforesaid trip-bowl;

Fig. 23 corresponds with Fig. 5 and is a part cross-section viewed from inside the loom endframe, and

Fig. 24 is a timing diagram to illustrate the action of the safety device illustrated in Figs. 18 to 23.

As previously stated the main object of the invention is to provide improved means for driving, stopping and, in certain circumstances, reversing looms, especially heavy looms of exceptional width, such driving means under manual control bringin up the crankshaft and co-driven parts to their normal running speeds in a short period of time corresponding to about 60 degrees or less of the crankshafts revolution, and such stopping means, under manual or automatic con trol, or both, disconnecting the drive and arresting all the moving parts of the loom, including the slay, in a short period of time corresponding to about 30 degrees or less of the crankshafts revolution, such said stopping means being initiated automatically by reason of either the shuttle failing to enter the shuttle box at the proper time or any one of a number of Weft forks detecting the absence of weft in the shed at or shortly before the time when the shuttle is normally due to enter the box, and such reversing means, under manual control, enabling the slay, after it has been so arrested in its forward movement, to be returned at will to its back position or thereabouts, during which return movement the crankshaft and its co-driven parts are caused to make a partial revolution in the reverse direc tion, thereby re-opening the last shed in which the fault occurred.

The said improved driving means for looms consists of a novel combination of a flywheel, a friction clutch and a friction brake, which clutch and brake'are controllediby a common operating lever as herein later described. While thesingle- ."plate' construction of clutchand brake'shown in 1 respect to theirengagement in the manner described may be utilised without departing from the principle of the invention. It is of the utmost practical importance, however, that the clutchand brake inner members shall be of lightweight construction in order to facilitate their rapid acceleration when the clutch is engaged,

and, still more so, their rapid retardation when the brake is applied.

Referring to Figs. 1, 2 and 3 the flywheel l and clutch outer member 2, integral therewithyare mounted on a short primary shaft 3 (which may be tubular as shown or solid) which is supported in suitable bearings '4 and driven by an electric motor 5 by means of a flexible coupling-6, whereby the flywheel and clutch outer member revolve at motor speed.

A secondary shaft 7 is supported'in suitable bearings 8, in axial alignment with the said primary shaft, and is further supported at the end adjacent to the flywheel by the spigot'bearing 9 carried in the flywheel boss. Shaft 7 is preferably splined at 7a to receive the internally splined two part sleeve, the members 10a and 11a, of which are also externally splined to fit the internally splinedhubs2l0b and llb'respectively, of the clutch inner member 58 and the brake inner member i I. By this construction, the clutch and brake inner members are free to slide axially within certain limits along shaft 1 but are effectively keyed thereto.

The brake outer member I2 is prevented from revolving, and may be part of-or attached by bolts to the casing l3, which serves to support the bearing end-plate M and to enclose theflywheel, clutch and brake. The said casing is formed with an opening at the top for access-to the enclosed parts, which opening is normally closed by the cover l5.

A common shipper-sleeve I6 is slidably mounted on or concentric with the secondary shaft 1 between the clutch and'the brake, and its axial movement is controlled by fork-lever l1 pivoted on pins I3a carried in the casing l3. Rocker pins 'i'la, carried in the said fork-lever, engage the gimbal-ring i8, which by means of rocker pins i6a, transfers the movement of fork-lever I! to the shipper-sleeve it. The fork-leverl'! projects downwards through a hole formed in the bottom of casing 13, and also through a corresponding hole in the subsidiary bedplate 25.

The brake presser-plate I20. is a slidable fit in the brake outer member i2, and (as shown-also by Fig. 3) projections l2b on the brake presserplate engage correspondingly shaped notches formed in the brake outer member l2, so that the said brake presser-plate is also prevented from revolving.

The clutch presser-plate 2a is similarly fitted in the clutch outer member 2, so as to revolve with the flywheel I.

The clutch presser-plate 2a andbrake'presserplate l2a are fitted with screwed rings and l2c, respectively each of such rings being provided with'edge-notches for C-key actuation and also with a number of spaced holes, one of which is engaged by a spring plunger IQ for locking purposes. These screwed rings :are adjusted to provide the desired axial movement'of the presser plates'in response to thenormalrockin'g moveneither of these parts revolves.

--ment--;of the fork-lever l1 and corresponding "axial movement of the shipper-sleeve H5.

The said shipper-sleeve directly engages ring 12c screwed into the brake presser-plate l2a, as Ring 20 screwed into the clutch presser-plate 2a, both of which are normally revolving, is engaged by the shipper-sleeve through the anti-friction thrust bearing'20.

The return movement of the presser plates 2a and [2a is effected by spring plunger 2|, acting on projections 22; and [2b.

.As'shown in Fig. l, the brake spring 22, adjustably anchored at 22a, is acting on fork-lever ll, which by the means already described is causing the brake inner-member or disc H to be clamped between the brake presser-plate 52a and the adjacent fiat surface of the brake-outermember !2, the consequent friction acting to stop shaft 1 (if this is revolving when the brake is ap plied), and to hold it stationary. At the same time, with lever I! in the stop positionshown in Fig. 1, the shipper-sleeve being displaced towards the brake, the clutch presser-plate 2a, under action of its spring plungers 2!, is correspondingly displaced towards the brake, whereby the clutch inner-member I0 is free from endpressure and is not driven.

Movement of link 23 in the direction of the arrow (Fig. 1) causes lever I! to be rocked in the same direction, in the course of which movement the brakeis first'released and the clutch then engaged, while due to such movement the brakespring 22 is further extended.

Conversely, when link 23 is released, the brakespring 22 rocks lever I! in the opposite direction, in the course of which movement the clutch is first disengaged and the brake then applied.

-When fork-lever I! is in its midway position, the brake is disengaged, but the clutch has not yet been engaged.

The necessary speed reduction from the motordriven primary shaft to the loom crankshaft or other driven shaft of the loom) consists preferably of an enclosed worm-gear followed by a pair of spur-gears, in which case the worm-shaft becomes the said secondary shaft as shown in Fig. 1.

In the preferred construction, the casing l3, carrying the bearings for the primary shaft and enclosing the flywheel clutch and brake, is bolted to the worm-gear box 26 in axial alignment with the worm-shaft I. The motor 5 and the wormgear box, the latter with the said casing bolted to it, are mounted on a subsidiary bedplate 25, which in turn is slidably mounted on the loom soleplate 26 at the driving end of the loom, as shown in Figs. 4 and 5.

The worm-wheel shaft 21 is extended. towards the loom end-frame28, and keyed on the said shaft is a spur-pinion 29, which meshes with a spur-wheel 30 keyed on the projecting end of the loom crankshaft 3|, which is provided with an outer bearing 32 mounted directly on the loom soleplate 26.

-In order'that the loom may be readily adjusted to run at its optimum speed, arrangements are included to facilitate changing the spur-pinion 29 for anotherhaving a different number of teeth, in which case, the spur-gear centre distance is adjusted to suit by sliding the subsidiary bedplate 25;along the loom soleplate 26 in a line parallel to the loom end-frame 23. When the spurgearacentres have'been correctly adjusted in this manner, the subsidiary bedplate 25 is bolted down to the loom so1eplate25yas indicated at points 25a, where the be'dplate is provided with slotted bolting-down lugs. Guide strips are preferably provided, as indicated at 2611 in Figs. 2 and 5, to maintain the bedplate and soleplate in correct relative alignment, also screw adjustment as shown at 25b, in Figs. 4 and 5, as a means for adjusting and maintaining the correct centre distance for the spur-gears.

The worm-wheel shaft 2'5 is provided. with an outer-bearing 21a, carried on, so as to move with, the subsidiary bedplate 25.

The above described driving and stopping gear is normally controlled by manual operation of the usual long control rod 35 extending the full width of the loom along the breast rail. The said control rod is hinged to the starting lever, and both are retained in their run positions by looking over a primary toggle included in the linkage connecting the starting lever to the fork-lever for actuating the clutch and brake. Automatic stopping is achieved by tripping (in any suitable manner) a secondary toggle or toggle-pair also included in the said linkage, upon which tripping action the loaded brake-spring acts almost instantaneously to disengage the clutch and apply the brake, during which action the long control rod and starting lever remain stationary in their run positions, with the advantageous result that the very appreciable retarding action caused, in known construction, by their inertia is entirely eliminated, and consequently the time taken to bring the brake into action is correspondingly and very appreciably reduced.

By the described means comprising the said clutch and brake acting on a shaft normally running at the speed of the electric motor used to 7 drive the loom, in combination with the said practically instantaneous tripping action of the secondary toggle for effecting disengagement of the clutch and full application of the brake, the whole of the moving parts of the loom are arrested and brought to a standstill in a short period of time corresponding to about 30 degrees or less of the crankshaft revolution, and without injurious shock, while the motor then continues to drive the primary shaft together with the flywheel, the clutch outer member and the clutch presser-plate, the stored energy of which assists the motor to bring the loom very quickly to its normal running speed when the clutch is again engaged.

Referring to Figs. 6a, 7a and 8a, the long horizontal control rod 35 is pivotally connected to the long arm 35a of the starting lever 36, which is of bell-crank form. This lever is pivoted at 360 on a bracket 3'! bolted to the end-frame 28 at the driving end of the loom. When the starting lever 36 is pulled over by means of the control rod towards the end-frame, the projection 36d finally abuts against a stop-screw 38b carried in the bracket 3?, the starting lever being then in the run position as shown by Fig. 8a, when its short arm 36b extends approximately horizontally towards the end-frame 28.

A transmission lever 39, also of bell-crank iii,

10 constructed and centrally hinged together at 40b to form the aforesaid secondary toggle or togglepair.

Their own weight tends to keep the two links 46 and 4| in their locked position as shown in Figs. 7a and So, when the central hinge pin 40b is just below a straight line passing through the two end pivot pins 3% and 3%, such locking action being limited by a finely adjustable stopscrew 40a.

The brake-spring 22 (Fig. 1) acting through link 23 and connected by any suitable intermediate linkage to the vertical link 34, which is connected to and actuated by the transmission lever 39, acts to maintain the said toggle pair in compression and, therefore, in their locked position as above described, and consequently throughout all manual operation of the control rod for normal starting and stopping purposes, the said toggle pair acts as a simple compression link connecting the short arm 36b of the starting lever to the upright arm 3% of the transmission lever. Thus, when the control rod is manually moved, together with its connected starting lever, from their stop position, shown by Fig. 7a, to their run position shown by Fig. 8a, the short arm 35b swings down approximately to the horizontal, while, due to the locked toggle pair 38 and 45, then acting as a simple compres sion link, the upright arm 39b of the transmission lever is forcibly displaced towards the loom end-frame and its horizontal arm 39a is correspondingly raised, whereby, against the opposing pull of the brake-spring 22, the brake is first released and the clutch then engaged to start the loom. As the startinglever completes this movement and the projection 36d abuts against the adjustable stop-screw 381) its short arm 361) forms a toggle lock (the aforesaid primary toggle-lock) in combination with the said locked toggle-pair 4B and 5| which are still acting as a simple compression link, and consequently the starting lever is locked in the run position against the pull of the brake-spring, as shown in Fig. 8a.

Initial manual movement of the control rod 35 in the opposite direction unlocks the said primary toggle, when the brake-spring acts to return, or to assist in the manual return of the parts to the stop position, shown by Fig. 7a, whereby the loom is stopped.

When the parts are locked in their run position as above described and shown in Fig. 8a, the brake-spring may be allowed to disengage the clutch and apply the brake very rapidly indeed by tripping the locked toggle-pair 4G and 4|, during which tripping action the control rod 35 and the starting lever 36 remain completely stationary in their run positions, while as shown in Fig. 6a, the tripped toggle-pair collapses in an upward direction thus allowing the brake-spring to act as above described.

The said toggle pair, after it has been tripped automatically to stop the loom, is readilyrestored to its locked position by simple manual return of the control rod 35, together with its attached starting lever 36, to the stop position, as shown by Fig. 7a, in the course of which movement the links 40 and il, comprising the toggle pair, straighten out and then, due to their own weight, resume their locked position in readiness for re-starting the loom.

- In some cases, the long control rod 35 may be dispensed with and the starting lever 36 fitted with a suitable handle for direct manual operation.

The intermediate-linkage connecting the forklever i! to the horizontal arm 39a. of the transmission lever may take any convenient form, such as that illustrated in Figs. 4 and 5, wherein, the link 23 (connected to the fork-lever H as shown in Figs. 1 and 2) extends through a hole in the end of the subsidiary bedplate 25 and is pivotally and adjustably connected to lever 33, which is itself pivoted at 33:11. A loaded compression sprin 23a is preferably fitted to the outer end of link 23 so as to cushion the clutch engagement and follow-up slight wear of the frictional surfaces of'the clutch inner member H]. The effective length of link 23 is adjusted by means of locknuts 23?) when the position of the bedplate 25 is changed to suit a different size of pinion 29 fitted to shaft 2?. The lever 33 is thence connected by the horizontal link 33a to a lever 331) secured to the rocker-shaft 330, while the lever 3911, also secured to the said rocker-shaft, is

connected by a vertical link 34 to the horizontal arm 35a, of the said transmission lever 39.

The above described secondary toggle or toggle pair 69 and Al may be automatically tripped in the event of the shuttle failing to enter the shuttle-boxand open out the swell at the proper time, whereby, as already described, the whole of the moving parts of the loom, including the slay, are brought to a standstill by the said friction brake in a. very short period of time corresponding to about 30 degrees or less of the crankshafts revolution, with the slay having moved through little more than the first half of its forward movement, so dispensing with the use of, and the attendant troubles caused by the customary dagger and frog mechanism a a direct means of arresting the forward movement of the slay.

in the construction preferred for attaining such automatic stoppage of the loom, a light stoprod 22 (see Figs. 9, 10 and 10a) mounted on the slay 43 and controlled by a spring 44 and feeler levers 45 adapted to rest against the shuttlebox swells 16 in the usual manner, is provided with a light dagger blade or dagger 41, which is freely hinged on the said stop-rod 42 near the driving end of the loom. The dagger 41 is supported and its angular position thereby controlled by an adjustable dog 48 secured to the stop-rod alongside the dagger.

When the slay 43 is moving forward and neither of the boxes contains a shuttle, the dagger 5? is adapted, at a suitable point in the slays forward movement, to engage and displace a trip-lever 56 (see Figs. 8a and 8b) pivoted on a vertical axis under the breast rail 28a near the end-frame 28 at the driving end of the loom.

If, however, during the slay forward movement the shuttle enters the shuttle-box at the proper time, the swell 46 at the front of the box is opened out, and, as shown by dotted lines in Fig. 10, the feeler-lever 45 resting thereon rocks the stop-rod 42 together with the dog A8 secured thereon with the result that the front end of the dagger 4'! is lowered so as to pass below the triplever 50 without engagement, in which case the loom continues in motion.

The trip-lever 5U, pivoted at 500, is provided, as shown by Figs 6a to 8b, with a short arm 50a which is connected by a short horizontal link 5| to a lug or arm 41a formed solid with link 4| of the aforesaid secondary toggle or toggle-pair in such a manner that when the slay 43 i moving forward and for the stated reason (or for any other reason causing the dagger to be held up. in its engaging position) the dagger engages with and displaces the trip lever 50, the first part of such displacement (inpractice, equal to a small fraction of an inch) servesrby link connection 5|, to unlock and trip the toggle-pair 4c and il, (as shownin Fig. 6a) thereby-stopping the loom by the retarding action of the brake with the slay having moved through little more than the first half of its forward movement, thereby preventin damage to the warp, the'reed and the shuttle in the event of the latter remaining in the shed.

The collapsing movement of the two links 40 and M comprising the toggle-pair, swings the trip-lever 50 around out of the path of the dagger 11, as shown by Figs. 6a and 6b, in which position the trip-leveroffers no obstruction to the free oscillation of the dagger, together with the stoprod and its feeler levers, during subsequent manual insertion of a shuttle into one of the empty boxe in preparation for restarting the loom.

After the toggle-pair has been restoreclto its locked position, in the manner already described, and the control rod is again moved into the run position to start the loom, the-link 5| causes the trip-lever 50 to swin back to its operative position, as shown in Figs. 8a and 8b.

The dagger 41 may be held down against the dog is by a spring 47a to ensure the dagger following the rapid downward angular movement of the dog. The use of the dagger freely hinged on the stop-rod and positively controlled only in the upward direction by the dog secured to the stop-rod, in the manner'already described, serves to prevent damage to the stop-rod'and its attached parts if the dagger has already engaged the trip-lever when the-shuttle enters the box later than normal.

With the same general effect, the dagger 41 may be secured directly to the stop-rod 42, so dispensing with the dog 48, if so desired.

The above described automatic stopping action in the event of the shuttle failing to enter the shuttle-box at the proper time, may be made further conditional upon any one of a number of weft-forks, suitably spaced along and supported on the slay, detecting the absence of weft inthe shed at or-shortly before the time when the shuttle is normally due to enter a box, in which event, the stop-rod dagger is retained in its upper or engaging position (even though the shuttle duly enters the box at the proper time) and by actuating the trip-lever effects prompt stoppage of the loom as already described.

In the preferred construction of such weft stop-motion, the details of which may be varied without departing from the principle of the invention, two weft-forks are spaced on the slay at'a distance from each end equal to about one third of the reed-width. These two weft-forks are actuated inunison by a cam em on the loom crankshaft 3!, in the particular manner herein later described.

Referring to Figs. 11, Ila, 12, Band 14, each weft-fork consists of a-fork-head or boss 52 pivoted at 530 me stand 53 fixed to the front face of the slay 43, the said boss having provision for clamping therein or thereto one or more wire prongs 54, which project from the boss towards the reed. The shuttle race and slay are slotted to form a recess opposite each fork in the usual manner as shown at 43a.

Midway in its length, the boss 52 takes the shapeof apushing pawl, the nose 52a of which