US1703471A - Dobby mechanism for looms - Google Patents

Description

Feb. 26, 1929. 1,703,471

c. D. BROWN 1 DOBBY MECHANISM FOR LOOMS Filed Feb. 14, 1928 2 Sheets-Sheet 2 Inventor. Carl D. Brown byiuad wkw Patented Feb. 26, 1929.

UNITED STATES 1,703,471 PATENT OFFICE.

CARL 1). BROWN, OF HOPEDALE, MASSACHUSETTS, ASSIGNOR T DRAPEB CORPORA- TION, 0F HOPEDALE, MASSACHUSETTS, A CORPORATION OF MAINE.

DOBBY MECHANISM FOR LOOMS.

Application filed February 14, 1928. Serial No. 254,303.

This invention relates to the'control of a pattern mechanism for a loom andmore particularly for such a pattern mechanism as employed in connection with a loom dobby. In certain types of such mechanism the pattern cylinder, which usually also comprises a pattern chain carried thereby, is driven by; a driving shaft and this drlvmg shalt has...

journalled thereon a constantly driven element, such, for example, as a sprocket wheel,

the sprocket wheel, is rotating idly onthe shaft and thus has a constant tendency to r0- tate the shaft and therewith the pattern cylinder. When such undesired rotation takes place the pattern is shifted, destroying the proper repeat, and the goods being woven are spoiled. To prevent this it has been common heretofore to provide some such mechanism as a notched diskon the shaft with a spring pressed roller engaging this disk. Such a mechanism, however, acts to produce a drag on the main shaft when it is rotating and driving the usual pattern cylinder, thus resulting in an unnecessary expenditure of power and wear of the parts. i v

The present invention has for its ohiect to provide construction in which, when the constantly driven element is unclntched from the driving shaft, the driving shaft will sinmltaneously be locked against rotation so that the continued idle rotation of the driven element on the shaftcannot act to, effect undesired rotation of the shaft and consequently of the pattern cylinder. p

The further object of the invention is to provide a construction forsecuring thisre sult which shall be inherently incapable of producing drag or retardation of the'driving shaft when it is being driven by the constantly driven element to effect the rotation of the pattern cylinder. 1

These and other ob 'ectsand features of the invention will appear more fully from the accompanying description and drawingsand will be particularly pointed out in the claims. The drawings illustrate a simple and preferred form of the invention as applied to the pattern mechanism of an ordinary type of loom dobby. As this type of dobby mechanism is well known and familiar to those skilled in the art and as the present inventlon relates only to a particular feature of control, it is only necessary to illustrate and describe in detail those parts of the mechanism With which the selected embodiment of the invention is associated. In the drawings:

Fig. 1 is a side elevation of a portion of the dobby mechanism., i

Fig. 2 is a view in end elevation looking. toward the right of the construction shown inFig. 1. I

Fig. 3 is a detail in top plan view. The loom pattern mechanism hereinv selected for a disclosure of apreferred form of the invention is that of a familiar type of loom dobby wherein the dobby indicating fingels are operated by risers carried by a pat tern chain runningover and driven by a cylinder and wherein a multiplier chain is employed under the control of which the pattern cylinder ceases rotation or dwells for predetermined periods in accordance with. the character of the pattern being woven.

In the construction illustrated, the dobby indicating fingers 1 are controlled by risers on a pattern chain 2 running over and driven by the cylinder 3 mounted on the shaft 4 journalled in the frame 5, This shaft 4=has secured or clutched'thereto a worm wheel 6 and this worm wheel, and consetp ientlytho shaft 4;, is normally;driven by a worm 7 secured. to a shaft 8 joiirnalled in the frame and extendingtransversely of and beneath the shaft 4. r j v A constantly driven element such as a sprocket wheel 9 having a hub 10 is jour nalled on the shaft 8 and this sprocket wheel is constantly driven, as by a sprocket chain 11, from a suitable source such ning shafts of the loom. A suitahleclntch is provided between this constantly driven element 9 and the shaft 8; In the construe tion illustrated the sprocket Wheel 9 is slidable longitudinally on the shaft 8 and the cooperating clutching elements are formed by a lug 12 projecting laterally from the sprocket wheel and a polygonal collarv 13 secured at'l l to the shaft 8. It will thus be seen that when the sprocket wheel 9 and its hub 10 is slid to the left, viewing Fig. 1, to bring the lug 12 into engagement with the collar 13, the shaft 8 will be driven and will in turn drive the as one of the runand facing'the member .15.

pattern'cylinder and when the sprocket wheel and hub are slid. to the right to disconnect the clutch, that the rotation of the shaft 8', and consequently of the pattern cylinder, will cease, but this constantly driven sprocket wheel with its extended hub Will continue to rotate idly on the shaft 8.

Such a disconnection of the driven element from the shaft 8 is what takes place when a multiplier chain is employed to enable the pattern cylinder to stand still predetermined interv is for predetermined periods during which the pattern not to 'be changed. But it will be observed that when this disconnection. of the driven element from the shaft takes place, the driven clen'ient, such as the sprocketwhcel, is constantly running, and often for an extended period of time, and necessarily with considerable friction on the shaft 8. This has a constant tendency to rotate the shaft 8 and thereby to rotate the pattern-cylinder and shift the pattern with obvious undesirable results.

In the construction illustrated, there is provided a pair of cooperating; locking members, one fixed on the dohby frame and the other rotatable with the shaft. These locking members are normally unlocked andthus have no effect whatever and produce no drag or retardation of the driving shaft and pattern cylinder. When, however,- the clutch is disconnected to stop the rotation of the pattern cylinder, these locking members are automatically locked and remain locked so long as the clutch is disconnected and thereby prevent the undesired rotation of the driving shaft. The fixed locking member is shown as a disk-like structure concentric with the shaft 8 and secured to or forming a part of the frame and having in its face, near its periphery, the notch 16. The cooperating locking member is shown a dog;

.17 pivoted at 18 to a disk-like structure 15) concentric with, and secured to the shaft 8 This disk 19 is n'orided at its periphery with a notch to guide and support the free end of the dog 17. This dog straddles the shaft 8 and is so proportioned'as to swing by ivity on its pivot into the unlockedpos den shown in Fig. 1. A helical compression spring 21 surrounds the shaft 8 between the hub 10 of the.

constantly driven element and the dog 17 and this spring is of such a length as to be inert when the locking elements are unlocked and the clutch is connected or with the parts in the position shown in Fig. 1 lit will be seen therefore that if the constantly driven element 9 with its hub 10 he slid on the shaft 8 to disconnect the clutch elements 12 and 13,. the spring 21 will be rendered. active and will force the locking dog-ll'against the disk 15 so that the free end of the dog. will lin me-diately or during the first rotation drop into the notch 16 and thus the locking members will be locked and any rotation of the shaft 8 prevented. This will continue so long as the clutch members are disconnected. When the constantly driven element is slid in the opposite direction and the members of the clutch are re-engaged, thespring 21 will be rendered inert and the dog 17 will swing out of locking engagement with the notch 16.

As this invention is particularly concerned with a (lobby mechanism, the cooperating" clutching elements and cooper: locking elements are under control of the pattern mechanisms of the dohhy with the pa ticulez. purpose in mind, as already pointed out, of insuring that the pattern cylinder which controls the dobby indicating fin.- s shall be p"wented from shifting when stopped by a multiplier pattern chain and until its move ment is to continue. I

A multiplier chain 2 is shown running over a sprocket wheel journalled on the shaft l and driven by a ratchet wheel 24 connected thereto, which ratchet whee: is actuated by a pawl on the oscillating rocker 26 of the dobhy. A shield 27 pivoted on the shaft l and having an m 28 normally held depressed by spring 29 stands normally in a position such as shown in Fig, 1 and prevents the pawl in its retracting stroke from catching the teeth of the re and wheel 24 so that the multiplier chain stands idle.

In the construction illustrated, a bell crank lever fulcrumed on. the (lobby frame at 30 has one arm 31 resting on the multiplier chain and the other arm 32 formed in. two parts adjustab-ly connected together by the slot and bolt construction and having at its lower end a pin 3-1- engaging a groove in the hub 10 of the constantly driven element. This bell crank lever normally has the arm 31 resting; on a low point, as shown in Fl 1, of the multiplier chain and with its arm 32 holding the constantly driven element clutched to tl, shaft 8. lever is held in this position by a s conneetin the arm 31 to another arm 37 pi oted at 30 and carrying a smmith-faced detont 38 riding against the teeth in the ratchet wheel 24:. The spring 29 already referred to is connected to the free end o the arm 3'7. One of the dobby indicating lingers is v provided with a laterally projectin arm 39 connected by a link 40 to the arm 28 of the shield 27.

This bel crank position as long as high points on the multiplier chain come under the arm 31 and during this period although the constantly driven element 9 is rotating on the shaft 8, that shaft is locked against rotation and thus the pattern cylinder is held in the desired position without any danger of shifting therefrom. VJhen the pattern cylinder is to continue its operation, a low point in the multiplier chain comes beneath the arm 31, allowing it to drop, and consequently the constantly rotating member is shifted back, the clutch members 12 and 13 re-engage, the locking member 1? falls out of the notch in the locking member 15, the shaft 8 is rotated, the pattern cylinder moves the riser from beneath the indicating linger 39, the shield 27 is swung by the spring 29 into normal position preventing the pawl 25 from operating the ratchet 23 and the parts again stand in the position shown in Figs. 1 and 2. p i

In the preferred construction illustrated the high point in the multiplier chain holds the clutch elements clutched and the locking members disengaged while the low point holds the clutch disengaged and the locking members locked but the invention in its broader aspects is not to be limited to the particular type of multiplier chain nor otherwise than as required by the claims.

lhe sequence of operations which talre place in either stopping or startingthe pattern cylinder follow each other with such rapidity that they may be recorded for practical purposes as occurring simultaneously.

The drag on the shaft 8 by a single idle rotaa tion of the constantly driven element 9 is usually insufficient to rotate the shaft and conuontly but one notch 16 shown in the ring member 15 so that the locking membors are locked within the period requii for one rotation of the element 9, but even this period may be shortened by increasing the number of notch Having thus described the invention, what is claimed as new, and desired to be -s cured by Letters Patent, is:

1. In a loom dobby mechanism of that type wherein the drivingshaft for the usual pattern chain is c riven by a constantly rotating el ment journalled thereon and connected thereto and disconnected therefrom by a clutch, and wherein a multiplier chain is employed, thecombination therewith of normal- 1y disengaged cooperating lockingmembers, one fixed on the machine frame and the other rotatable with the driving shaft, and means for securing the locking engagement of said locking members during the period the multiplier chain is active and the clutch is unclutched and the drlven element 1s rotating idly on the shaft, thereby to prevent undesired movement of the usual pattern chain.

2. A pattern mechanism for looms comprising a pattern cylinder, a driving shaft acting when rotated to rotate the cylinder, a constantly driven element journalled on the shaft, a clutch for connecting said driven element to, and disconnecting it from, the shaft, normally unlocked means for locking the shaft against rotation, and automatically controlled means for simultaneously disconnecting the clutch and effecting the look ing of the locking means and for simultaneously effecting the unlocking of the locking means and connecting the'clutch whereby,

when the clutch is disconnected, the rotation of the driven element on the shaft cannot act to rotate the shaft and thus shift the position of the pattern cylinder and, when the clutch'is connected, the shaft and therewith the pat: tern cylinder will be rotated. a

3. In a loom pattern mechanism, a driving shaft, a constantly driven element journalled and longitudinally slidable on the shaft, co-. operating clutch members on the shaft and driven element connected and disconnected by sliding the driven element on the shaft, cooperating normally unlocked locking members, one fixed on the frame and the other rotatable with the shaft, a spring on the shaft extending between the driven element and the locking member on the shaft and inert when the shaft is running and when rendered active acting to effect the locking of the locking members, and automatically controlled means for sliding the driven element on the shaft into unolutched position and thereby rendering the spring active to effect the locking of the locking members whereby the continued idle rotation of the driven element on the shaft cannot actrto givean undesired r0- tation to'the shaft. I

A pattern mechanism for a loom dobby comprising a pattern cylinder, a driving s'ha I cylirider, a constantly driven elen'ient 'journailed on the shaft, a clutch for connect- ,acting when rotated to rotate the ing said driven element to, and discoir necting it from, the shaft, normally unloclred means for locking the shaft against rotation, a multiplier pattern chain, normally lnactive means for driving the multiplier '1 J pattern chain and means COIltlOllQCl by the pattern cylinder for simultaneously renderlng active the driving means for the multiplier patternchain, disconnecting the clutch and moving the locking means into locking posi ion and after a predetermined interval controlled by the multiplier pattern chain for simultaneouslymoving the locking means into unlocking position, connecting the clutch and rendering inactive the driving means for the multiplier pattern "chain.

In testimony whereof, I have signed my name to this specification.

CARL 1). BROWN.

Images