US2888955A - Positive and automatic warp let-off apparatus for power looms - Google Patents

Description

AJune 2, 1959 FusAKlcHl KoNDo 2,388,955

PosTTTvE AND AUTOMATIC wARP LET-OFF APPARATUS Fon POWER Looms Filed Aug. 28, 195e United States Patent F PGSITIVE AND AUTOMATIC WARP LET-OFF APPARATUS FOR PWER LOOMS Fusakichi Kondo, Tado-machi, Kuwana-gun, Mie-ken, Japan Application August 28, 1956, Serial No. 606,642

8 Claims. (Cl. 139--99) This invention relates generally to power looms and more particularly to a positive and automatic warp letoff apparatus for power looms.

The apparatus according to the invention is characterized in that it has a plurality of freely mounted warp letoif rolls between the warp beam and the back rest roll; and in that it has two groups of ratchet mechanisms arranged side by side in front of the frame and driven by oscillatory motion of the lay sword. One group of ratchet mechanisms drives the said warp let-off rolls the other group drives the cloth driving roll to keep up constant driving speeds of the warps and the cloth with an optional speed ratio. The apparatus is further characterized in that it has changing and separating mechanism for the said ratchet mechanism to enable, if necessary, reversing or idling motion without changing the tension of the warps; and in that the warps are guided successively in counter directions to the said warp let-off rolls the two ends of which are operatively connected to the said warp beam and the back rest roller in the directions that the warp let-off` rolls may be pressed toward each other by the warp tension so that the warps are let oi by the let-oif rolls with automatic changeable pressure between them which is proportional to the warp tension.

The principal object of the present invention is to provide a practical, simple and easily operated apparatus which can weave uniform cloth and reduce breaking of warps let off from the warp beam by positive and automatic warp let-off and cloth take up, Iwhich takes place intermittently from the oscillatory motion of the lay sword, having a regulated constant peripheral speed ratio.

Up to the present time, two types of equipments have been used for let-off warps in looms. The one type uses a passive method which has a brake on the warp-beam and supplies warps by pulling them against the braking force, the other type makes use of a positive method which supplies warps by rotating the warp beam positively by a mechanism which responds to the tension of warps. In both methods, however, the warp supplying motion is caused by the tension of warps themselves which are to be let olf. In the first mentioned type the warp beam is rotated directly by the warp tension and in the second mentioned type the machine is constructed so as to adjust the mechanism which positively drives the Warp beam by a movable back rest which responds to the tension of warps. As a result, a strong tension is constantly applied on the warps, especially the tension on warps which can withstand the least tensile strain, for example cotton threads in woolen yarn, becomes so great that it causes non-uniformity of Warp winding on the beam and finally break.

And, moreover, because of the time lag between the change of warp tension and let-oli or take-oil motion of warps, the warp let-off is not uniform and it causes stripes in the woven goods.

This can result in low work speeds or rate, expense ,for alteration of products and the necessity of extra raw Patented June 2, 1959 materials. In order to avoid these shortcomings, ac. curate machine adjustment yand a high degree of operator skill in weaving are necessary and in spite of these careful attentions, satisfactory results cannot be expected.

In the present invention, however, these difficulties are avoided because the take-off or let-off mechanism of the warps is correlated with the cloth take-up mechanism and they are both driven positively in order to give a certain speed ratio of cloth winding to warp supply; as a result a constant tension is applied to the warps, warp supply is uniform, and breaking of warps and aws in the cloth are avoided.

We can think of another method for rotating the warp beam by the power shaft to supply warps mechanically and positively but in this method, keeping constant the rotating speed of the warp beam, warps tend to be strained as the outside diameter of the warp beam decreases. Because of this tendency it is necessary to gradually decrease the cloth take-up mechanism speed, for instance, and other corresponding considerations. But it is very diiiicult to accomplish all this.

In this invention, not the warp beam but a plurality of freely operatively combined let-off rolls between the warp beam and the back rest roller are mechanically driven, so when the rotating speed of the let-oi rolls is constant, the warp let-off speed is kept constant independently of the outside diameter of the warp beam Winding and when the cloth takeup mechanism speed is kept constant, by making constant the rotating speed of the cloth driving roller, the change of warp tension due to the change of spool diameter is completely excluded.

In addition, the warp let-off rolls are driven by worms and are cooperatively, operationally combined freely with each other so they are pressed toward. each other with pressure proportional to the warp tension, and as the result it is very easy to install and exchange the warp and to meet any sudden change of the warp tension, i.e. the shock due to oscillation, to avoid the slip of warps and the stripes of woven goods.

As the warp beam is freely supported the application of a little warp tension is able to `drive the warp beam and, even in the case of mix weaving, non-uniformity of the warp spool and the Warp breaking are avoided. Experience with the invention indicates that rolls having a relatively high coefficient of friction are most suitable for the warp let-oif rolls for wool looms.

ln the present invention, the Warp let-oil? rolls and the cloth driving roll are separately driven by two groups of ratchet mechanism which are driven by the oscillating motion of the lay sword. Each group is arranged side by side in front of the loom frame and is separated for the warp and for the cloth and driven through their own riving mechanism, so the operator can easily control the driving condition of the two groups and the forward, stoppin-g or backward motion of either. The warp let-V oif and the cloth take-up can be easily and` separately performed. As the two groups of ratchet mechanism each have two ratchet wheels, forward and backward, and engaging claw members, they can be arranged to operate forward, backward or stop at one time and by one operaion.

Since shrinkage between the warps and the woven cloth is almost within a fixed limit, for Woolen fabrics about i2% around 5%, when the peripheral speeds of the warp let-off rolls and the cloth `driving roll are determined corresponding to the mean value of shrinkage, the same number of cogs for both ratchet wheels are used for the mean shrinkage value and different number of cogs are used selectively in other cases and so half number of ratchet wheels is sufficient for responding to a. range of various speeds.

assente- Asa result of the arrangement mentioned above, there is a decrease of warp breaking decreasing downtime of the loom. Experiments show the working rate Yincreases from70% Yto more than 90% fo'r woolen fabrics; stripes in woven cloth are eliminated making the cloth uniform, the weight of the product-s is standardized, excess use of raw material is avoided, operational limits of looms are extended because problems caused both by hardness and thickness of materials and products are eliminated. Moreover, adjustment and control of the machine is so easy that unskilled workers can produce high class cloth quite easily.

A preferred embodiment of this invention is illustrated by way of example in the accompanying drawings, in which:

Fig. 1 is a partly sectional side elevation view of a warp let-olf apparatus according to the present invention,

Fig. 2 is a fragmentary front view of a portion of the apparatus shown in Fig. 1,

Fig. 3 is a fragmentary perspective View showing a ratchet mechanism of the apparatus of Fig. 1.

Referring `to the drawings 1 is a warp beam and warps 2 spooled on 1 are led through four warp let-off rolls 3 to a back rest roll 4, then through a heald 5 and a reed 7 attached to an upper part of a lay sword 6. The warps are Woven into a cloth 8, and are guided by a breast beam 9 and a cloth driving roll 10. The woven cloth is taken up by a cloth take-up roll 11. The lowermost letoff roll 3 is pivotally mounted on a fixed axis and the other rolls 3 are pivotally mounted on a member having a slot 3b schematically shown in Fig. l so that their axes may move toward the axis of the lowermost roll 3. The four warp let-olf rolls 3 are each freely operatively combined or caused to cooperate as herein later described, and the warps 2 are guided interlaced on opposite sides of the rolls 3 in sequence, and both ends of the warps 2 are operatively associated with the warp beam 1 and the back rest 4 in dependence upon the directions that the warp let-of`f rolls are pressed mutually by the tension of the warps 2. A crank shaft 12, through a connecting rod 13 causes oscillatory movement of the lay sword 6 on a pivot shaft 14. A connecting piece 16 is `carried on `an end of a lever 1S which is fixed on the l-ay sword 6 connecting, to the lay sword, a part of an L-shaped piece 1S which is pivoted on a shaft 17.

On a rotating shaft 19 is freely supported a piece 20, which has two elongated guide slots a and b on it, and a guide pin 21 is inserted and fixed through a guide slot c on the L-shaped piece 18 and the guide slot b above mentioned. On the rotating shaft 19 are fixed ratchet wheels or cogwheels 22 and 23 one above the other which have opposite peripheral cogs `as shown. A handle or wheel 24 is disposed adjacent to the cogwheels on shaft 19. Claw members 26 and 27 are joined by a pin 2S in the guide slot a as to operatively engage with the cogs of the ratchet wheels 22 and 23. The other end of the rotating shaft 19 is connected to another rotating shaft 31 through a universal joint 28, a connecting rod 29 and a universal joint 30;

On the rotating shaft 31 is xed a bevel gear 32, with which is engaged a bevel gear 33. A driving shaft 34 is fixed to the bevel `gear 33 and supports two worms 35 on it, the lower one of which is xed and the upper slidably keyed, and they are engaged to two worm wheels 36 which are fixed on the two alternately arranged warp let-off :rolls 3. A lever 38 is provided with a pin 40 disposed in a guide slot of the frame maintaining contact with both a roller 37 attached to the lay sword 6 and the back rest roller 4. An adjusting piece 41 is attached to the lever 38. On the other end of the reed 7 used for driving filling is fixed another lay sword 6', corresponding to the lay sword 6 above mentioned, which is connected to the crank shaft 12 through a connecting rod 13' and is pivotally joined to the shaft 14. From the lay sword 6', corresponding to the elements associated Awith lay sword 6 are disposed a lever 15', a connecting piece 16', an L-shaped piec 1S', a pin 21', a piece 20', claw members 26' and 27', ratchet wheels 22 and 23', a rotating shaft 19' and a handle 24' which are attached to the other side of the frame. A wonm 42 fixed on the rotating shaft 19 is engaged to a worm wheel 43 which is fixed to the cloth driving roll 10.

The action of the apparatus is as follows:

When the crank shaft 12 turns, the lay swords 6 and 6' are oscillated on the shaft 14 by the connecting rods 13 and 13' and the reed 7 on the upper part of 6 and 6' makes one driving operation for each rotation of the i crank shaft 12. At the same time, the roll 37 on the lay sword 6 pushes the lever 38 which in turn makes an oscillating motion around the shaft 40 and controls the warp tension by shifting the back rest roll 4 in connection with the motion of the heald 5 which is driven by other mechanism (not shown).

The levers 15 and 15', the connecting pieces 16 and 16', the L-shaped pieces 18 and 18' and the pieces 20 and 20' move in the direction shown by arrows due to the oscillating motion of the lay swords 6 and 6'. For each movement, the claw members 26 and 26' drive the ratchet wheels 22 and 22', and which also drive the rotating shafts 19 and 19' intermittently. The shaft 19, in turn, drives the driving shaft 34 intermittently through the connecting rod 29, the rotating shaft 31, the bevel gears 32 land 33 'and it also drives the warp let-off-rolls 3 through the worms 35 and worm wheels 36. By these motions, the warps 2 are supplied intermittently from the four adjacent warp let-olf rolls 3. On the other hand, the rotating shaft 19' drives the cloth driving roll 10 through the worm 42 and the worm wheel 43, and the woven cloth 8 is taken up intermittently to the cloth take-up roll 11 with a constant running speed which is determined by the let-olf speed of the warps 2 having no connection with the outside diameter of the cloth taken up on the roll 11, through the ratchet mechanism which is related to the lay sword 6 and a friction disc mechanism (not shown).

It is possible to change the ratio of the warp supplying speed to the cloth take-up speed corresponding to various kinds of cloth material by using different ratchetV wheels 22 and 22. When it is necessary to miss the beating for some reason, the claw members 26, 27 and 26', 27' can be disconnected with the ratchet wheels 22, 23 and 22', 23' by a connecting mechanism fixed to 26, 27 and 26', 27 (not shown) and the shaft 19 and 19' stop. Therefore, the supply of the warps 2 and takeup of the cloth 8 are also stopped leaving only the weft supplying and beating in motion.

The machine can be reversed by engaging the claw members 27 and 27' with the reversely turning ratchet wheels 23 and 23'. In this case, the warp let-off rolls 3, the cloth driving roll 10 and the cloth take-up roll 11 are driven in the reverse direction but the warp beam 1 is driven Vin the same direction, and so the direction of movements of the warps 2 and the cloth 8 is reversed, the warps 2 are relaxed between the warp let-oil: rolls 3 and the warp beam 1 but no relaxation takes place between the warp let-off rolls 3 and the back rest roller 4, and a simple reverse can be done without loosening the cloth take-up roll 11 and turning the warp beam 1 by hand. Because the connection and disconnection of the claw members 26, 2'7 and 26', 27 to the ratchet wheels 22, 23 and 22', 23' can be made together as Well as separately through or without the connecting mechanism, the warps 2 or the cloth 8 can be supplied or taken up by controlling the wheels 24 or 24' disconnecting one of the connecting mechanism concerned.

I do not desire to limit myself to the particular construction and arrangement of the parts herein shown and described, since it is obvious that many changes can be made without departing from the spirit and scope of my invention as defined in the appended claims.

What I claim is:

1. In a loom having oscillatably driven lay swords and warp left-oit and cloth take-up mechanisms, the take-up mechanism comprising a driven cloth take-up roll, a plurality of removable and interchangeable intermittently driven ratchet wheels, a cloth delivery roll driven intermittently by said ratchet wheels for delivering linished cloth to the take-up roll, means cooperating with said lay swords for driving said ratchet wheels at least in one direction at selected speeds Within a predetermined range of speeds, said let-off mechanism comprising a plurality of cooperating let-olf rolls, a warp beam, means driven by said ratchet wheels for driving at least one of said let-off rolls at selected speeds within a predetermined range of speeds thereby to let-oi warp from the beam in selected speed ratios relative the speed of the cloth delivery roll.

2. In a loom having oscillatably driven lay swords and warp let-off and cloth take-up mechanisms, the take-up mechanism comprising a take-up roll driven at substantially a uniform speed, a plurality of removable and interchangeable intermittently driven ratchet wheels, a cloth delivery roll driven intermittently by said ratchet Wheels for delivering finished cloth to the take-up roll, means cooperating with said lay swords for driving said ratchet wheels at least in one direction at selected speeds Within a predetermined range of speeds, said let-ott mechanism comprising a plurality of cooperating let-cfr" rolls, a Warp beam, means driven by said ratchet Wheels for driving at least one of said let-ott rolls at selected speeds within a predetermined range of speeds thereby to let-oil warp from the beam in selected speed ratios relative the speed of the cloth delivery roll.

3. In a loom having oscillatably driven lay swords and warp let-ott and cloth take-up mechanisms according to claim 2, in which some of said ratchet Wheels drive said cloth delivery roll and other ratchet Wheels drive said let-olf rolls, said wheels driving the let-olf rolls being adapted to drive the rolls with a peripheral speed 5 percent greater than the peripheral speed of the cloth delivery roll.

4. In a loom having oscillatably driven lay swords and warp let-ott and cloth take-up mechanisms according to claim 2, in which said ratchet wheels comprises two pairs of wheels, each pair having the wheels arranged for opposite rotation, one of said pairs cooperating for driving said cloth delivery roll in two directions and the second pair cooperating for driving the let-olf rolls in two directions, said pairs of ratchet wheels being replaceable with other wheels having a selected number of teeth determined as a function of the shrinkage factor of the warp material.

5. In a loom having oscillatably driven lay swords and warp let-off and cloth take-up mechanisms, the take-up mechanism comprising a driven cloth take-up roll, a plurality of removable and interchangeable intermittently driven ratchet wheels, a cloth delivery roll driven intermittently by said ratchet wheels for delivering finished cloth to the take-up roll, means cooperating with said lay swords for driving said ratchet wheels at least in one direction at selected speeds Within a predetermined range of speeds, said let-oir mechanism comprising a plurality of cooperating let-oft rolls, a warp beam, means driven by said ratchet wheels for driving at least one of said let-0E rolls at selected speeds within a predetermined range of speeds thereby to let-olf warp from the beam in selected speed ratios relative the speed of the cloth delivery roll, and a tensioning roll cooperating with said let-oi rolls and said lay swords for maintaining a preselected substantially constant tension on the warp during all operations of the loom.

6. In a loom having oscillatably driven lay swords and warp let-off and cloth take-up mechanisms, the take-up mechanism comprising a driven cloth take-up roll, a plurality of removable and interchangeable intermittently driven ratchet wheels, a cloth delivery roll driven intermittently by said ratchet wheels for delivering nished cloth to the take-up roll, means cooperating with said lay swords for driving said ratchet wheels at least in one direction at selected speeds within a predetermined range of speeds, said let-off mechanism comprising a plurality of cooperating let-olf rolls, a warp beam, means driven by said ratchet wheels for driving at least one of said let-oli rolls at selected speeds within a predetermined range of speeds thereby to let-oit warp from the beam in selected speed ratios relative the speed of the cloth delivery roll, means for selectively rendering said delivery roll and said let-oir rolls inoperative thereby to preclude driving by said wheels, and means for selectively operating the let-olf rolls and cloth delivery roll manually.

7. In a loom having oscillatably driven lay swords and Warp let-off and cloth take-up mechanisms, the take-up mechanisms, the take-up mechanism comprising a driven cloth take-up roll, a plurality of removable and interchangeable intermittently driven ratchet wheels, a cloth delivery roll driven intermittently by said ratchet wheels for delivering finished cloth to thel take-up roll, means cooperating with said lay swords for driving said ratchet wheels at least in one direction at selected speeds within a predetermined range of speeds, said let-oli mechanism comprising a plurality of cooperating let-olf rolls including a pair of driven let-olf rolls, a warp beam, means driven lby said ratchet Wheels for driving said pair of letoi rolls thereby to let-ott warp from the beam in selected speed ratios relative the speed of the cloth delivery roll, and a pair of friction rolls disposed alternately with said let-oir rolls and cooperating therewith.

8. In a loom having oscillatably driven lay swords and warp let-oi and cloth take-up mechanisms according to claim 7, in which said pairs of let-oit rolls have their longitudinal axes disposed radially of each other and substantially in the same plane, including means pivotally mounting one of said driven let-olf rolls in a lixed position, means for mounting the other rolls radially above of said last mentioned roll with their axes freely movable radially of one another, the warp being disposed over the uppermost let-oir roll between the rolls and alternately on opposite sides of alternate rolls, and means comprising a warp tensioning roll cooperating with said let-01T rolls for maintaining a constant tension on the warp.

References Cited in the le of this patent UNITED STATES PATENTS 1,737,600 Lucas Dec. 3, 1929 2,303,297 Budzyna et al. Nov. 24, 1942 FOREIGN PATENTS 386,791 Germany Jan. 27, 1922

Images