US2712327A - Dobbies for looms - Google Patents

Description

July 5, 1955 F. DAVIES ETAL DOBBIES FOR LOOMS 6 Sheets-Sheet 1 Filed NOV. 6, 1952 ammo m 224% A TTOEA/fYIS July 5, 1955 F. DAVIES ET AL DOBBIES FOR LOOMS 6 Sheets-Sheet 2 Filed NOV. 6, 1952 11V VEYVTOES F/Lcwz m ATTOE/VEXIY July 5, 1955 F. DAVIES ET AL DOBBIES FOR LOOMS 6 Sheets-Sheet 3 Filed Nov. 6, 1952 m mnthhhu Ha I L I I I July 5, 1955 Filed 1952 DAVIES ET AL 2,712,32 DOBBIES FOR LOOMS 6 Sheets-Sheet 4 /VVENTOES 1M I 24,

Filed Nov. 6, 1952 DAVIES ETAL DOBBIES FOR LOOMS 6 Sheets-Sheet 5 July 5, 1955 F. DAVIES ET AL 2,712,327 DOBBIES FOR LOOMS Filed Nov. 6, 1952 6 Sheets-Sheet 6 By J 7 F/r1/ KW 13% W, WQ M A TTOENEYJ Unite States Patent 055cc Z,7l2,327 Patented July 5, 1955 2,712,327 DOBBIES FOR LOOMS Frank Davies and John Kennedy Pitts, Didsbury, Manchester, England, assignors to The British Cotton Industry Research Association, Manchester, England, a British association Application November 6, 1952, Serial No. 319,044 14 Claims. .(Cl. 139-71) This invention relates to double-lift open-shed dobbies for looms and is particularly but not exclusively applicable to positive knife dobbies.

It is usual for positive knife dobbies to have an oscillating baulk moving in a vertical plane and the movealso movable In a vertical plane and pivoted to the ends of the baulks. The control of the hooks to bring them into engagement or disengagement with the oscillating knives is eifected by feelers which in turn are under the mechanism to be located 'inside' the dobby mechanism to provide the :interengaging necessary, 'to enable the knives to :oscillate the baulks. Under certain conditions from stops.

The object of the present :invention :is "to :provide 'an improved and simplified construction of dobby mechto the pattern mechanism;

Fig. 3 is a part sectional end elevation on the line 3 3 Fig. 2.

Fig. 4 is a section on the line 4-4, Fig. 6, illustrating how the feelers are controlled by the pattern chain.

Fig. 5 is a section on the line 5-5, 'Fig. 6, and showing warp shed closed.

Fig. 6 is an end view of Fig. 5 looking from the right.

Fig. 7 is a detail view of the means illustrated in Figs. 5 and -6.

'In the drawings, and referring particularly to Fig. '1 thereof, the jack 10, ofwhich there are several according oted upper and lower hooks 15, 16. The ends of the baulkare fashioned with bosses 12a and 12b adapted to contact the back stops 13, 14 and also to be engaged by upper and lower knives or griffes 17, 18, as they move The upper hook 15 is alsofashioned with a downwardly and rearwardly projecting portion or tail 15d on the opposite side of pivot 15x from the hook portion 15a,

and abutting the upper face of said tail is the upper .the dobby mechanism. The inner or forward portion 15a of the hook 15 is heavier than the tail portion 15d, so that the hook is loaded to tilt in a clockwise dithe baulk 12 is somewhat similar in'construction and operation to the upper hook 1'5, and also has atcomparatively short, inner or forward portion 16a having a rabbet or notch 16b to engage the lower front stop 20,-and

hook 16 is also cut away at 16c to receive and engage the lower griffe or knife 18. In addition to the outer portion or tail 160?, the lower hook has a weighted portion 16c, whereby it is caused to tilt on its pivot 16x in a counterclockwise direction to disengage from the lower front stop 20 and engage the knife 18 from underneath under the control of bell-crank feeler 26 pivoted on shaft 26b. The upper end of the vertical limb of the bell-crank feeler 26 has a cam face 26a adapted to be engaged by another peg of the pattern mechanism in manner similar to the cam face 21a of the feeler 21 for the upper hook. The feelers 21 and 26 are springloaded into engagement with the pegs of the pattern mechanism, by a spring 27 extending between them forwardly of their pivots 2.2 and 26b, respectively.

As illustrated in Figs. 2 and 3, the upper griffe or knife 17 extends between and is flexibly mounted on the upper ends of a pair of bell-crank levers 2b, 28a pivoted at 29, 29a the said levers being located at each side of the machine with the knife 17 extending transversely across all the upper hooks. The proportions of the bell-crank levers and the location of the pivots thereof are so arranged that the knife can move angularly in an are substantially corresponding with that followed by the pivots of the upper hooks when the baulks are rotated about the centres of the pivots of the lower hooks. The lower knife or griife 18 is similarly supported or carried by a pair of bellcrank levers 30, 30a pivoted at 31, 31:: but the bell-crank levers 30, 30a are opposed with respect to the bell-cranks 28,. 28a, and links 32, 32a connect the free ends of the bell-crank levers, so that if said levers are pivoted or moved angularly in a clock-wise direction, see Fig. 2, the upper knife 17 will move to the right while the lower knife 18 will move to the left.

It will be understood that the angular path of movements of the lower knife 18 substantially follows the arc of movement of the lower hooks during pivoting movement of the baulks about the centres of the pivots of the upper hooks.

in order to give the required angular movement to the bell-cranks, 28, 28a, 3%, 30a and thereby oscillate the knives, the bell-crank levers are oscillated by cams. As shown in Fig. 2 for one side of the dobby, one of the arms of lever 30 is provided with a cam follower 33 rotatable on a stud 33x, said cam follower being located in a cam groove 34, fashioned in a cam 35 mounted on a cam shaft 36. Thus it will be seen that lever is oscillated by cam 35 through cam follower 33 while the lever 28 is oscillated by the lever 30 through link 32. On the other side of the machine (see Fig. 3) the lever 28a is oscillated by a cam 35a mounted on shaft 36 and av cam follower 3311 while the lever 30a is oscillated by the lever 28a through link 32a. The cam shaft is driven by a pair of bevel gears 37, 38, see Fig. 3, the bevel gear 38 being mounted on a driving shaft 39 driven in turn from the loom top shaft (not shown). The cam groove of each cam is so shaped that it will cause each griife or knife in turn to relieve all the adjacent hooks from their front end of each inward traverse, and in conwith the flexible mounting of the knives will also provide for the requisite slating or staggering of the knives during their osc'llating movement. For the latter purpose the cams are so shaped that one end of each knife is advanced relatively to the other end, so that the knife moves forwardly in an inclined position, but at each end of the stroke the knife occupies a noninclined position.

Also mounted on the cam shaft 36 is the driving member 40 of a Geneva motion, the driving pins thereof being identified by the numerals 41 and 42. The driven member 43 of the Geneva motion is mounted on the pattern barrel shaft 44 and by the driving connection illustrated in Figs. 2 and 3 the knives 17, 18 are oscillated in timed relationship with the pattern control mechanism.

- on which the warps are located.

It is usual to operate several jacks by the dobby mechanism and each jack has its own baulk with upper and lower hooks. The cam grooves 34 oscillate the knives 17, 18 in known manner and the hooks 15 and 16 pivot into or out of engagement with their respective knives under control of the pivoted feelers (see Fig. 4), to operate the jacks 10 in manner required to weave The cam grooves 34 are so proportioned and shaped that the knives on the backward movement of their traverse, engage the bosses 12a, 12b, at each end of each baulk to move same a sufiicient distance to relieve the hooks from the front stops 19, 20 whereupon free pivotal movement of the hooks can occur, by reason of their unbalanced construction, it allowed to do so by the feelers 21, 26. If a hook is prevented by the pattern chain (operating through the feelers) from engagement with its associated knife, then on outward movement of said knife the hook rests against the front stop.

It will be appreciated from the showing of Fig. 1 that the weighting or loading of the bottom hooks at their tail or rearward portions urges them to pivot to engage the lower knife 18 from underneath.

As is well known in the textile trade it is desirable when weaving artificial silk to close theshed and equalize the tension on the warp threads if and when the loom is stopped for any length of time, for example over-night, in order to prevent stretching of the said threads.

In the improved dobby construction, provision is made for closing the shed and reference is now made to Figs. 5, 6 and 7, wherein is illustrated means therefor. Said means comprises an upper rod 45 extending above and transversely of all the tails 15d of the upper hooks, and a lower rod 46 above and extending transversely of all the feelers 26, and said rods are supported by and between the upper and lower ends of a pair of bell- crank levers 47, 47 mounted on shaft 22 journalled in bearings 49, 49. In order to give the requisite pivotal movement to the shaft 22 to lower the upper rod 45 into contact with the tails of all the upper hooks to disengage them from the upper knife 17 and engage them with the upper front stop 19, an operating handle 50 is provided pivoted at 51, and at one end of said lever is an arcuate slot 52 in which is located a pin 53 fixed to the upper end of a substantially vertical arm 54 on the shaft 22. It will be appreciated that when the handle 50 is moved to the position indicated in dot-dash lines in Fig. 7, the pin 53 will be moved to the dotted position (Figs. 5 and 7), and consequently a partial angular movement will be imparted to the shaft 22 through the arm 54, and such movement will pivot the bell-crank levers 47 and cause the rod 45 to make contact with all the tails of the upper hooks and pivot them out of contact with the upper knife or gritfe, thereby relieving simultaneously all the upper hooks and holding same free from engagement with the upper knife. Similarly and simultaneously the lower rod 46 is engaged with the lower feelers 26 and moves them to the dotted position, Fig. 5, allowing the bottom hooks 16 to rise for engagement with the lower knife 18.

It will be understood from the foregoing description that, as used in the specification and claims hereof, the terms front, forward and forwardly have reference to that side of the dobby mechanism on which the warps are located, while back, backward, backwardly" and rearwardly have reference to the side opposite that What we claim is:

1. A double lift open-shed dobby for looms comprising a plurality of baulks each having an upper hook and a lower hook pivotally mounted on the upper and lower ends, respectively, of the baulk, upper and lower front stops adjacent the respective ends of the baulk for preventing forward movement of the hooks and of the associated supporting ends of said baulk s, a pair of upper and lower oscillatory knives positioned forwardly of said stop engaging portion extending forwardly, and a tail portion extending rearwardly, of its pivot, pivotally 2. A double lift open-shed dobby according to claim 1 wherein the knife engaging portions of said hooks are relatively short and have notches formed therein for engagement with said front stops.

3. A double lift open-shed dobby according to claim 2 wherein the weight of each hook is so distributed relagagement with said feeler members.

4. A double lift open-shed dobby for looms comprising any desired position.

A double lift open-shed dobby according to claim 8 e 9. wher in s bers, respectively.

aid hook raising and feeler member moving 10. double lift open-shed dobby according to claim 1 tions and shedding is progressive across the loom.

12. A double lift open-shed dobby according to claim 11 wherein the cam mechanisms at the opposite ends of the knives References Cited in the file of this patent UNITED STATES PATENTS Goodyear July 1,

Heatley et al. July 15,

Wiget June 29,

Wiget Nov. 25,

FOREIGN PATENTS Great Britain Feb. 10,

Great Britain Jan. 29,

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