US2813551A

US2813551A - Loom take-up motions

Info

Publication number: US2813551A
Application number: US460535A
Authority: US
Inventors: Shorter Sydney Alfred
Original assignee: British Cotton Industry Research Association
Current assignee: British Cotton Industry Research Association
Priority date: 1950-07-01
Filing date: 1954-10-06
Publication date: 1957-11-19
Anticipated expiration: 1974-11-19

Description

Nov. 19, 1957 s. A. SHORTER LQOM-TAKE-UP MOTIONS 2 Sheets-Sheet 1 Filed Oct. 6, 1954 N 1957 s. A. SHORTER 2,813,551

LOOM TAKE-U13 MOTIONS Filed Oct. 6, 1954 '2 Sheets-Sheet 2 mvsn'rpR SYDNEY ALFRED Snmvm United States atent Office 2,813,551 Patented Nov. 19, 1957 2,813,551 LooM TaKE-UP MOTIONS Sydne y Alfred Shorter, Didsbury, Manchester, England,

assignor to The British Cotton Industry Research Association, Didshury, Manchester, England Application October 6, 1954, Serial No. 460,535 Claims priority, application Great Britain July 1, 1950 13 Claims. (Cl. 139--312) present invention is based upon closer investigation and appreciation of the problem.

Take-up motions of the kind with which this invention is concerned operate by stepping down, through atrain of gearing, a relatively large motion, continuous or in steps, and so producing the required small rotation of the take-up roller operating on the woven cloth, the lineal value of which rotation may correspond for example to a single pick of a cloth having 80 picks per inch, and therefore not be readily capable of being regulated with any degree of accuracy by direct means (i. e. by the exact movement without reduction gearing).

This kind of take-up motion, in which the train of mechanism may include, for example, a train of spur gear wheels, and/or a worm and worm wheel, is liable to a number of repetitive or cyclic variations respectively arising from imperfect shaping of the teeth of one or more of the various gear wheels, or from eccentricity of the mounting of one or more of the wheels, and from other causes, and even when the lack of uniformity is very slight, and in fact when the utmost practicable resources of engineering technique are employed in the construction of such a train of gearing mechanism, there is always a contingent liability to visible barring imperfection with many types of fabrics.

The present invention has for its object an improved gearing for a take-up motion which can readily be fitted to different types of looms, and by the use of which, in? spite of reasonable errors and tolerances in its manu-. r facture, there would be substantial elimination of visible barring arising from non-uniform take-up of the cloth due to such repetitive or cyclic errors in the gear wheels and ordinary tolerance errors.

i It will be understood that in a take-upmotion of the kindreferredtqerrors of uniformity will in general be compounded of a number of variations which are of a cyclic or repetitive nature arising from different parts of the mechanism. Thus if one revolution of a particular gear wheel corresponds to 30 picks, there will be a liability for cyclic generation? in the cloth of weft bars of a 30 pick wave length. Similarly, if in the geartrain there isa wheel, such as a 24-tooth change wheel, having the pitch of its teeth corresponding to 24 picks, there will be a liability for cyclic generation in the cloth .of weft bars of a 24-pickjwave length. Again, if the last gear wheel or a take-up roller having a circumferential length of say 15 inches has say teeth, there will be a repetitive generation in the cloth of weft barring at 4 inch spacing. In any train of gearing there will inevitably be a inumber of such revolution (cyclic) and tooth (repetitive) periods of varying take-up length.

The present invention is based upon the appreciation that the perceptibility of any particular cyclic or repetitive variation of normal proportions i. e. arising from normal manufacturing tolerances and errors, depends upon the take-up length of the cycle, or repetition, in other words that there is, as regards barring a visual range of cyclic or repetitive wave length outside of which the eiiect of barring from normal tolerances and errors is not perceptible in the fabric though irregularities may still be there in undiminished amplitude. Thus, on the one hand, an irregularity of sufiiciently long wave length is in general imperceptible, partly because of the gradualness of the change in pick spacing, and partlybecause visual judgments of the kind involved can only be made over a restricted area.

On the other hand, an irregularity of sufiiciently short only an average impression extending over a number of.

picks, which averaging increases with distance.

1 It has been found by research that weft barring from gearing of normal practical errors and irregularities is imperceptible except within a visual range, i. e. when the wave length is between inch (3.2 mm.) approximately and lO'inches (254 mm.) approximately. It follows therefore from such discovery that if a take-up gearing can be designed which avoids the generation of irregularities within such wave length range, barring will be substantially eliminated in spite of irregularities arising from normal mechanical errors and tolerances.

According to the present invention a take-up mechanism for a loom comprises in combination, a take-up roller having a circumference of at least 10 inches; a driven gear wheel directly coupled to said take-up roller so that one revolution of said driven gearwheel produces one revolution of said take-up roller; a driving gear wheel connected to said driven gear wheel for driving the same, said driven and driving gear wheels being so dimensioned that one revolution of said driving gear wheel produces a corresponding peripheral movement of said take-up roller of not more than Ms inch and a train of gear wheels connected .to said driving gear wheel for driving the same, said gear wheels of said train of gear wheels being so dimensioned that one revolution of any of the latter gear wheels produces not more than such a rotation of said driving gear wheel which produces a correspondingperip heral movement of said take-up roller of A2 inch.

,The change speed gearing aforesaid maybe characterised inlthat the alternative ratio of the change speed gear train includes at least one possible step-up ratio and in that the large step-down ratio of the last gear train is proportionally greater than that dictated by the revoluwave length tends to be evened. oufin the process of weaving by the sliding of the weft over the warp which takes place before the various picks mm.) approximately take-up movement; or further characterised in that the large reduction ratio in a single step such that one revolution of the driving wheel and one tooth movement of the driving wheel represents not more than /s inch (3.2 mm.) approximately take-up motion; or further characterised in that the ratio of the large step down is such that one revolution of the leading or driving gear wheel of that train and of all preceding gear wheels represents a lineal take-up of not more than 4; inch (3.2 mm.) approximately.

The invention also includes the method of driving the take-up roller of a loom through toothed gearing wherein the wheels of the gear train are so proportioned and arranged that one tooth movement of any gear wheel represents not more than /8 inch (3.2 mm.) lineal movement of the periphery of the take-up roller and one revolution of any one gear wheel represents not less than 10 inches (254 mm.) or not more than inch (3.2 mm.) lineal movement of the periphery of the take-up roller.

The invention also includes a woven textile fabric wherein the weft-way barring resulting from irregularities in the take-up mechanism of a loom has a wavelength of less than 4; inch (3.2 mm.) or more than 10 inches (254 mm.).

Although a take-up roller is commonly of inch (381 mm.) circumference the application of the present invention is facilitated by utilising a take-up roller of smaller circumference (say, for instance 10 inches (254 mm.)).

Inv the gearing for a take-up motion it is necessary to employ some means usually by change wheels for varying the number of picks per inch, and the possible variation should be large enough to cover the complete range of fabrics which the loom may be required to weave. In known designs of gearing for a take-up motion it happens that irregularities producing cyclic variations of take-up. within the range of wave lengths aforesaid are introduced by this part of the mechanism. Repetitive variations within such wave length occur from the teeth of the gear wheels nearest to the take-up roller. With the present invention it can still be arranged, as is common with many known loom take-up motions, that the gearing train includes a change wheel having the same number of teeth as the number of picks per inch required or a simple multiple thereof, without introducing cyclic or repetitive variations within the wave length aforesaid. The advantage of such arrangement is of course simplicity in setting up the loom for a required rate of take-up given in picks per inch.

In the accompanying drawings:

Fig. 1 is a front elevation of a loom take-up mechanism embodying change speed gear constructed in accordance with the invention.

Fig. 2 is a view looking from the left of Fig. 1, whilst Fig. 3 is a plan view.

In said drawings, the take-up mechanism comprises a counter-shaft 10 which is driven through chain sprocket 1 1 from the half-speed shaft (not shown) of the loom. Also mounted on the counter-shaft 10 is a bevel pinion 12 meshing with a larger bevel pinion 13 giving a 1:2 reduction ratio and slidably keyed on a vertical shaft 14 rotatably mounted in

bearings

15, 16. The bevel pinion 1-3 is loaded against a collar 14b for engagement with the pinion 12 by a spring 14a, and said pinion 13 can when desired be lifted out of mesh with pinion 12 by link 17 to interrupt the drive to the shaft 14. The link 17 is connected to a fork 17a having a pin 17b engaged with a groove 13a in the bevel pinion 13. The link is adapted to be actuated by a lever 17c. At the upper end of shaft 14 is a change pinion 18 which may have 30 teeth or 60 teeth. Below the change pinion 18 is a bracket 19 on top. of which is adjustably mounted a quadrant 20 carrying a carrier wheel 21 having 50 teeth meshing with the change pinion 18. The quadrant is adjustable in known manner about the axis of the changepinion 18. Journalled in the upper bracket 19 and in a lower bracket 22 is a shaft 23 carrying a single-start worm 24 and adapted at its upper end to receive any one of alternative change wheels 25 having teeth varying from 32 to 80, such teeth representing picks per inch of weaving when the pinion 18 has 60 teeth. The carrier wheel 21 is adapted to be engaged with such change wheel 25. Also mounted on the upper bracket 19 is setting hand wheel 26 having a tooth pinion 27 of 60 teeth mesh with a further toothed pinion 28 of 30 teeth the latter being mounted on the shaft 14.

The take-up roller 29 of 10 inch circumferential length has journalled on its shaft 29a a worm wheel 30, having on the outer end of its hub teeth 31 engaged with complementary teeth on the end of a hub 32 of a hand wheel 33, slidably keyed at 34 to the end of the shaft 29a. The worm wheel 30 has 150 teeth and is of course in mesh with the worm 24. Rapid take-up may be obtained by disengagement of the teeth 31 to permit rotation of the take-up roller (without the worm wheel 30) by the hand wheel 33., or alternatively more usual movement for manual take-up or let-back can be obtained by the hand-wheel 26 after disengagement of the

bevel wheels

12, 13.

In operation it will be observed that relative to the take-up roller 29 having a 10" circumferential length (254 mm.) one revolution of the driven worm wheel 30 represents 10 inch lineal movement of take-up, so that a worm wheel 30 having 80 teeth will produce by one tooth movement a permissible take-up movement of inch. Consequently, if the step-down transmission ratio between worm 29 and the worm wheel 30 is at least 80:1, one revolution of the worm 24 will produce no more than one eightieth revolution of worm wheel 30 resulting in a take-up motion of one eightieth of the circumference of take-up roller 29, that is 10 inches divided by 80, which is /8 inch. As the worm wheel 30 has 150 teeth, one tooth movement of such worm wheel. represents & inch (1.7 mm.) takeup movement which is less than 42 inch (3.2 mm.). Consequently, neither repetitive (tooth) nor cyclic (per revolution) errors can repeat within the takeup distance of inch (3.2 mm.) or 10 inches (254 mm.) from the worm wheel 30. It also follows that one revolution of the worm 24 can only produce a cyclic error representing 3 inch take-up and therefore outside the visual range aforesaid, and it obviously follows that tooth or repetitive errors from any of the

gear wheels

25,, 21, 18, 13 and 12, by reason of the 150/l step down ratio of the worm and worm wheel, cannot be anywhere near as large as inch (1.7 mm.) take-up distance and are therefore also outside the visual range. Cyclic errors from all the preceding gear wheels are all less than /s inch (3.2 mm). Taking the instance when the change pinion 18 has 60 teeth and the change wheel 25 has 32 teeth, it can be calculated that one revolution of the gear wheel 12 can produce a cyclic error equal to inch (1.6 mm.) take-up distance since the step-down ratio from gear wheel 12 to driven worm wheel 30 is 1. following equation is valid The When the change pinion 18 is changed for a 30 tooth wheel this cyclic distance is halved i. e. A inch and as is well known each tooth of the change wheel represents 2 picks per inch instead of 1 pick per inch as when change pinion 18 has 60 teeth. Obviously also when the change wheel 25 has more than 32 teeth one revolution of the change pinion 18 represents a take-up distance of less than /a inch (3.2 mm.). As regards the carrier wheel 21, which is described as having 50 teeth, one revolution will always represent a take-up distance or cyclic error of less than /8 inch (3.2 mm). In order to avoid cyclic errors within the visual range the carrier wheel 21 must not have more teeth than the larger change pinion 1 8. For

aside The invention is not limited to all the proportions of the gearing above described in so "far as they may be varied. without departing from the scope of the present invention. For example the worm wheel 30 could be provided with 100 teeth instead of 150, the same change wheel 25 could be used, the change-pinion 18 could have m 40 teeth and the carrier wheel 21 not more than 40 teeth. With this arrangement and still with a 10 inch (254 mm.) take-up roller the cyclic errors fromthe

gear wheels

18, 21 and are all as described in the preceding example, while the cyclic error of the worm 24 and the repetitive error of the teeth of the worm wheel represent a take-up distance of fore outside the visual range.

Equally it can be seen that with the 150 tooth worm wheel 30, a 15 inch (381 mm.) take-up roller29, change pinion 18 having or 20 teeth, a carrier pinion 21 having not more than 40 teeth and the same set of change wheels 25 having 32 to 80 teeth, the cyclic and repetitive errors will be exactly as those which occur'and have been described for the parts shown in the drawing.

It is equally clear that neither cyclic nor repetitive errors from

thebevel pinions

12, 13 can be within the visual range aforesaid.

What I claim is:

r 1. Change-speed gearing for the take-up motion of a loom comprising a reduction gearing giving a large ratio and including a worm and a worm wheel meshing therewith and preceded by a train of gear wheels, of which one gear wheel is changeable for varying the rate of take-up characterised in that such changeable gear wheel has teeth which in number are a multiple of the number of picks required per unit length, the change wheels preceding the worm and the worm wheel being located at a higher level than the take-up roller of the loom and adapted to rotate in a horizontal plane and being driven by a vertical shaft and bevelled gearing from the half speed shaft of the loom.

2. Change-speed gearing according to claim 1 further characterised in that the large step down ratio of the worm and worm wheel is such that one revolution of the worm correspondsto not more than inch (2.5 mm.) take-up movement. l l

Change-speed gearing according to claim 1 further characterised in that the ratio of the large step-down is such that one revolution of the leading or driving gear wheel of that step and of all preceding gear wheelsrepresents a lineal-take-up of not more than /8 inch' (3.2 mm).

4. A change-speed gearing according to claim 1 further characterised by clutch means disengaging the bevel gears, a hand wheel and further gearing meshing with the spur gearing for manually effecting take-up or let back whilst the gear is disengaged.

5. A change-speed gearing according to claim 4 further characterised in that the worm wheel is freely mounted on the take-up shaft and clutched to a further hand wheel slidably keyed on the shaft whereby the further hand- Wheel can be disengaged from the Worm wheel and the shaft rotated by the said further hand wheel.

6. The structure of claim 1 wherein the worm wheel is directly connected to the shaft of the take-up roller.

7. A take-up mechanism for a loom, comprising, in combination, a take-up roller having a circumference of at least ten inches; a driven gear wheel directly connected to said take-up roller so that one revolution of said driven gear wheel produces one revolution of said take-up roller; a driving gear wheel connected to said driven gear wheel 4 inch (2.5 mm.) and are there- M .6 a l. for driving the same, said driving gear wheel and said driven gear wheel being constructed to have a step-down transmission ratio of at least 80:1 so that one revolution of said driving gear wheel produces not more than one eightieth of a revolution of said driven gear wheel and" effects a corresponding peripheral movement of said takeup roller of not more than one eightieth of said circumference. thereof resulting in a take-up movement of not more than eighth of an inch; and a train of gear wheels connected to said driving gear wheel for driving the same, the step-down transmission ratio of said gear train be tween each of said gear wheels of said train of gear wheels and said driven gear wheel being at least 80:1 so that one revolution of anly one of said gear wheels of said train of gear wheels produces not more than one eightieth revolution of said driven gear wheel and a corresponding peripheral movement of said take-up roller of not more than one eightieth of said circumference thereof and results in a take-up movement of not more than one eighth of an inch.

8. A take-up mechanism for a loom, comprising, in

combination, a take-up roller having a circumference or at least ten inches; a driven worm gear wheel directly connected to said take-up roller so that one revolution of said driven worm gear wheel produces one revolution of said take-up roller; a driving worm connected to said driven worm. gear wheel for driving the same, said driving worm and said driven worm gear wheel being constructed to,have a step-down transmission ratio of at least 80:1 so that one revolution of said driving worm produces not more, than one eightieth of a revolution of said driven worm gear wheel and effects a corresponding peripheral movement of said take-up roller of not more than one eightieth of said circumference thereof resulting in a takeup movement of not more than one eighth of an inch; and a train of gear wheels connected to said Worm for driving the same, the step-down transmission ratio of said gear train between each of said gear wheels of said train 'of gearwheels and said driven worm gear Wheel being at least 80:1 so that one revolution of any one of said gear wheels of said train of gear Wheels produces not more than one eightieth revolution of said driven worm gear wheel and a corresponding peripheral movement of said take-up roller of not more than one eightieth of said circumference thereof and results in a take-up movement of not more than one eighth of an inch.

least ten inches; a

driven worm gear Wheel having at least 80 teeth and being directly connected to said take-up roller so that one revolution of said driven worm gear Wheel produces one revolution of said take-up roller; a driving worm connected to said driven worm gear wheel for driving the same, said driving worm mission ratio of at least :1 so that one revolution of said driving worm moves said driven worm gear wheel one tooth distance and produces not more than one eightieth of a revolution of said driven worm gear wheel and effects a corresponding peripheral movement of said take-up roller of not more than one eightieth of said circumference thereof resulting in a take-up movement of not more than one eighth of an inch; and a train of gear wheels connected to said driving worm for driving the same, the step-down transmission ratio of said gear train between each of said gear wheels of said train of gear wheels and said driven Worm gear wheel being at least 80:1 so that one revolution of any one of said gear Wheels of said train of gear Wheels produces not more than one eightieth revolution of said driven Worm gear wheel and a corresponding peripheral movement of said take-up roller of not more than one eightieth of said circumference thereof and results in a takeup movement of not more than one eighth of an inch.

10. A take-up mechanism for a loom, comprising, in

l r and said driven worm gear wheel be1ng constructed to have a step-down transcombination, a take-up roller having a circumference of at least 10 inches; a driven gear Wheel directly connected to said take-.up roller so that one revolution of said driven gear wheel produces one revolution of said take-up roller; a driving gear Wheel connected to said driven gear wheel for driving the same, said driving gear wheel and said driven gear wheel being constructed to have a step-down transmission ratio of at least 80:1 so that one revolution of said driving gear wheel produces not more than one eightieth of a revolution of said driven gear wheel and effects a corresponding peripheral movement of said takeup roller of not more than one eightieth of said circumference thereof resulting in a take-up movement of not more than one eighth of an inch; and a train of gear wheels connected to said driving gear wheel for driving the same, at least one of the gear wheels of said train of gear wheels being a change gear for varying the rate of take-up motion of said take-up roller, the step-down transmission ratio of said gear train between each of said gear wheels of said train of gear wheels and said driven gear wheel being at least 80:1 so that one revolution of any one of said gear wheels of said train of gear wheels produces not more than one eightieth revolution of said driven gear wheel and a corresponding peripheral movement of said take-up roller of not more than one eightieth of said circumference thereof and results in a take-up movement of not more than one eighth of an inch.

11. A take-up mechanism for a loom, comprising, in combination, a take-up roller having a circumference of at least ten inches; a driven gear wheel directly connected to said take-up roller so that one revolution of said driven gear Wheel produces one revolution of said take-up roller; a driving gear wheel connected to said driven gear wheel for driving the same, said driving gear wheel and said driven gear Wheel being constructed to have a step-down transmission ratio of at least 80:1 so that one revolution of said driving gear Wheel produces not more than one eightieth of a revolution of said driven gear wheel and eifects a corresponding peripheral movement of said take-up roller of not more than one eightieth of said circumference thereof resulting in a take-up movement of not more than one eighth of an inch; and a train of gear wheels connected to said driving gear wheel for driving the same, at least one of the gear Wheels of said train of gear wheels being a change gear for varying the rate of take-up motion of said take-up roller and having a number of teeth adapted to be a multiple of the picks required per unit length of a fabric woven in the loom, the step-down transmission ratio of said gear train between each of said gear wheels of said train of gear Wheels and said driven gear Wheel being at least 80:1 so that one revolution of any one of said gear wheels of said train of gear wheels produces not more than one eightieth revolution of said driven gear wheel and a corresponding peripheral movement of said take-up roller of not more than one eightieth of said circumference thereof and results in a take-up movement of not more than one eighth of an inch.

12. A take-up mechanism for a loom, comprising, in combination, a take-up roller having a circumference of at least ten inches; a driven Worm gear wheel directly connected to said take-up roller so that-one revolutionof said driven worm gear wheel produces one revolution of said take-up rollers; a driving worm connected to sald driven worm gear wheel for driving the same, said dI'lV- ing worm and said driven worm gear wheel being coning peripheral movement of said take-up roller of notl more than one eightieth of said circumference thereof resulting in a take-up movement, of not more than one eighth of an inch; and a train of gear wheels connected.

to said driving worm for driving the same, at least one of the gear wheels of said train of gear wheels being a change gear for varying the rate of t-ake up motion of said take-up roller and having a number of teeth adapted to be a multiple of'the picks required per unit length of a fabric woven in the loom, the step-down transmission ratio of said gear train between, each of said gear Wheels of said train of gear wheels and said driven worm gear wheel being at least :1- so that one revolution of any one of said gear wheels of said train of gear wheels produces not more than one eightieth revolution of said driven worm gear wheel and a corresponding peripheral movement of said take-up roller of not more than one eightieth of said circumference thereof andresults in a take-up movement of not more than one eighth of an inch.

13. Change-speed gearing for the take-up motion of a loom, comprising, in combination, a reduction gearing having a large step-down ratio including a Worm and worm wheel meshing therewith and a train of gear wheels preceding said worm, the step-down ratio from said worm to said worm wheel being such that one revolution of said Worm corresponds to not more than one eighth of an inch take-up movement, at least one gear wheel being changeable for varying the rate of take-up, said changeable gear wheel having teeth the number of which is adapted to be amultiple of picks required per unit length.

References Cited in the file of this patent UNITED STATES PATENTS 769,580 Anderson Sept. 6, 1904 1,748,000 Stone Feb. 18, 1930 2,130,979 Wirth Sept. 20, 1938 2,518,185 Rinne Aug. 8, 1950 FOREIGN PATENTS 596,739 Great Britain Jan. 9, 1948