US2750968A - Beat-up motion for looms - Google Patents

Description

June 19, 1956 KLE'lN 2,750,968

BEAT-UP MOTION FOR LOOMS Filed May 1'7, 1952 5 Sheets-Sheet 1 /z 1N VENTOR BY 4% EM ATTORNEY June 19, 1956 N. E. KLEIN 2,750,968

BEAT-UP MOTION FOR LOOMS F'iled May 17, 1952 3 Sheets-Sheet 2 ATTORNEY June 19, 1956 E, KLEIN 2,750,968

BEAT-UP MOTION FOR LOOMS Filed May 1'7, 1952 3 Sheets-Sheet 5 INVENTOR lrmrzjfleilg BY MMLZW ATTORNEY 2,750,968 Patented June 19, 1956 ice BEAT-UP MOTION FOR LOOMS Norman E. Klein, Pendleton, S. C., assignor to Deering Milliken Research Corporation, Pendleton, S. C., a corporation of Delaware Application May 17, 1952, Serial No. 288,428

4 Claims. (Cl. 139-190 This invention relates to looms for weaving textile materials and, more particularly, to beat-up motions for such looms.

In the operation of a loom, the lay, which carries the shuttle race plate and the reed, must oscillate between two fixed positions, the extreme backward position or back dead center, at which it is traversed by the shuttle, and the extreme forward position, front dead center, at which the reed forces or beats up the last filling or weft thread against the fell of the cloth being woven. The drive mechanism efiecting this oscillation is commonly referred to as the beat-up motion.

conventionally, the lay, pivoting about a fixed horizontal axis, is driven from a simple crankshaft rotated at a uniform rate, being connected to the crankshaft by means of a connecting rod. The motion of the lay effected by this arrangement is unsatisfactory in that the lay is caused to remain in its extreme forward position as long as in its extreme backward position.

It has been established that if it were possible to actuate the lay in such a fashion as to achieve an appreciable period of rest or dwell at back dead center the speed of the loom could be materially increased. Accordingly, several attempts have been made in the prior art to attain this characteristic. For example, complex linkage arrangements between the crankshaft and lay have been designed. While these, in a measure, accomplished the desired results, they added materially to the weight and inertia of the lay and, for this and other reasons, were impractical. Face cams were tried but these failed to impart a smooth motion. In a further attempt, elliptical gears were utilized; however, these were extremely costly to manufacture and were difiicult to maintain in proper operating adjustment.

It is, therefore, the object of the invention to provide an improved beat-up motion for looms which is light in weight, simple in principle and design, low in cost of fabrication and installation and which operates to lengthen that portion of the loom cycle which is devoted to the actuation and flight of the shuttle.

Additional objects will be apparent from a consideration of the following description, read in connection with the drawings, in which:

Figure l is a side elevation view of the instant invention in association with related parts of a loom of conventional design;

Figure 2 is a plan view of the structure illustrated in Figure l, with the warp threads omitted for clarity;

Figure 3 is an enlarged View of the pertinent portion of Figure 1, viewed from the inside of the loom;

Figure 4 is a sectional view along line 44 of Figure 3;

Figure 5 is a sectional view along line 55 of Figure 3;

Figure 6 is a sectional view along line 6-6 of Figure 5;

Figure 7 is a schematic view illustrating the principle of operation of the invention; and

Figure 8 is a schematic view illustrating a modification of the invention as shown in Figure 7.

In general, this invention comprises driving the .lay of a conventional loom through an epicyclic gear train, the internal member of the train or pinion being driven by a crankshaft around the inside of an external memher or ring gear fixed to the frame of the loom, making three revolutions about its own axis for each revolution around the gear. A connecting rod pivotally secured at one end to the lay is eccentrically connected at the other end to the pinion, the eccentric axis of the connecting rod being offset from the axis of revolution of the pinion an amount suflicient to cause the eccentric axis to follow as the pinion revolves a path having substantially the shape of an equilateral triangle.

Turning now to a detailed description of my invention, reference is made to Figure 1 which shows my novel beat up motion in association with certain related parts of a loom of conventional design. In this figure, the numeral 11 generally designates a loom having the usual side frame members 12 on which is journaled a crankshaft 13, driven at either end thereof by conventional means, not shown. The crankshaft, as usual, is provided with a crank portion 14 in the region adjacent each of the frame members 12. A lay 15 supported at each end thereof by lay swords 16 for pivotable movement about a horizontal axis 17 is disposed forwardly of the crankshaft 13. The warp threads W passing in sheet form between the frame members 12 and above the shaft 13 and lay 15 are separated by the action of the heddles 18 once per each cycle of operation of the loom, this separation defining a shed through which the shuttle 19 passes. It will be understood that the above elements are part of the equipment normally provided on looms and for that reason do not form a part of the instant invention except insofar as they function in cooperation therewith. The crankshaft driving means and the conventional loom members other than those specified have not been shown since they bear no particular relation to the operation of my improved motion.

The structure by which the present improvement is practiced is best shown in Figures 3 through 5. Each of the crank portions 14 on the crankshaft l3 rotatably carries a pinion 2t). Meshing with the pinion it} is an internally geared ring member 21 encircling the shaft and fixedly supported from the frame members 12 of the "m in spaced parallel relationship thereto. A semi-cylindrical bracket member 22 having an inwardly directed flange 23 may advantageously be utilized in supporting the ring gear 21, the bottom portion of the ring gear being attached to the inner end of the bracket member by any desired means, such as screws or the like, and the flange 23 at the other end of the bracket being secured to the inner face of the frame member 12 by suitable means such as bolts or by welding. Should further support for the ring gear be required, a brace member 24 attached to the top of the ring gear 21 and the frame 22 at its respective ends may be employed.

The ratio of the ring gear 21 to the pinion 29 is preferably 3-1,.i. e., the circumference and/ or number of gear teeth of the ring gear is three times that of the pinion. Thus, the pinion undergoes three revolutions about its own axis on the crank 14 for each revolution around the ring gear or about the axis of the crankshaft. I

Pivotably secured to the back side of the lay 15 as at v25 is one end of a connecting rod 26, the other endof 'the rod being eccentrically connected to the pinion 2t), the axis of eccentricity being indicated at X.

The location of the eccentric axis X with respect to the axis of revolution Y of the pinion 20 is quite critical if the desired operation is to be obtained and this radius bears a definite relationship to the radius of the crank arm, i. e., the distance between the axis of the crankshaft and the axis of revolution Y, and the length of the connecting rod 26. The ideal location of this eccentric axis is such that as the pinion makes one revolution around the ring gear the eccentric axis moves in the path of an epicycle, the sides of which are substantially the arc of a circle having a radius the length of the connecting rod. An approximation of such a curve is an equilateral triangle having slightly convex sides.

In practice, it has been determined that substantially the desired result will be obtained if the ratio between the eccentric radius, the crank arm radius and the length of the connecting rod is maintained at about 0.15O.30:l:3.5 9.5, the eccentric radius increasing as the length of connecting rod increases, all within the limits prescribed. If the precise location of the eccentric axis is required, the following equation can be solved for any given values of the crank arm radius and the length of the connecting rod:

where d is the length of the connecting rod, R is the radius of the crank and r is the radius of eccentricity.

Reasonably good approximations of this equation can be obtained if 1' equals 028R and a equals 9.42R or 1' equals 024R and d equals 4.73R.

While neither the above equations nor the approximations therefor yield a value for r which results in a period of absolute dwell for the lay, it has been determined that such is not required, provided that the lay does not undergo substantial movement, that is, it does not move from its back dead center position more than about five percent of the length of its throw.

It will be observed that if a period of dwell is to be obtained when the lay is in its back dead center position, with equal periods of time available for the beat-up and return strokes of the lay, the location of the eccentric axis radially of the axis of revolution of the pinion must be selected so that a straight line extending through the loci of the pivotable connection of the connecting rod with the lay when the lay is at its front dead center and back dead center positions will be perpendicular to a straight line drawn through the loci of two of the cusps of the epicycle and will intersect that line at substantially the mid point thereof. Stating this in a slightly different manner, if it is assumed that the eccentric axis follows a path which approximates an equilateral triangle, the eccentric axis should coincide with the locus of one of the apices of this triangle when the lay is in its front dead center position.

The connecting rod may be pivotally secured to the pinion in any desired fashion. In view of the fact, however, that the forces required to drive the lay of a loom are of considerable magnitude, it is preferred that a bearing surface of considerable dimension be provided at the connection of the connecting rod with the pinion 20. In accordance with this desideratum I have provided the pinion 20 with a disk member 27 integral with the pinion and spaced axially a short distance therefrom. The disk has its axis eccentric with the axis of the pinion and is formed with a bearing surface at its outer peripheral wall. This Wall is also provided with an outwardly directed bead 28. which mates with a groove 29 provided on the inner surface of the head of the connecting rod 26 to prevent inadvertent disengagement of the connecting rod from the disk.

With a view to facilitating the assembly and disassembly of the mechanism, the integral pinion and disk array is split or divided into substantially equal portions, the two portions being removably secured together by means of screws, such as the Allen head type, threadably embedded therein, as shown in Figure 6. The advantage of such a construction lies in thefact that a conventional one-piece crankshaft can be utilized, the two portions of the disk and pinion array being adapted to be removed, fitted around the crank portion 4 of the shaft and reassembled in their operating position.

The connecting rod best adapted for use with my invention is of the conventional type having a split circular head or crank portion provided with a bearing surface on the inner face thereof, the split portion being removable from the rest of the rod for assembly with the disk.

The operation of the present invention is best shown in Figure 7, corresponding positions of the drive motion and lay being indicated respectively by the same letters of the alphabet in capitalized and small form. Assume that the lay is in its front dead center position a and that the crankshaft and pinion-disk array is in its forward posittion A. If the crankshaft is revolved to from this position in a counterclockwise direction, the lay moves to its position b and the pinion-disk array to its position B. Continued revolution of the crankshaft through about 33 brings the lay to its back dead center position 0 and the pinion-disk array to its position C, the lay substantially remaining in this position While the crankshaft revolves through 2 radians or about 114 to position C. Thereafter, about 33 additional degrees of revolution of the shaft brings the piniondisk array to its position B and the lay back to its position b and upon the crankshaft completing the last 90 of the cycle, the lay returns to position a. In other words, during the front 180 of revolution of the crankshaft the lay moves from position b to a and back to b, while during the back 180 of revolution of the shaft the lay moves from position b to c and finally back to b. It will, therefore, be apparent that the lay is accorded a prolonged period of dwell at its back dead center position with an accelerated beat-up to the front dead center position and return therefrom.

While the arrangement shown which produces approximately similar lay movement in both the beat-up and return is preferred on account of its symmetry and freedom from vibration, it will be apparent that the mechanism may be adjusted to give a different movement in the beat-up and return strokes respectively, this effect being obtainable by suitable location of the epicyclic mechanism with respect to a straight line extending through the loci of the rod-lay connection at the front and back dead center position.

A slightly different form of my invention is schematically illustrated in Figure 8, the modification consisting of the use of a ring gear to pinion ratio of 2 to 1 instead of 3 to 1, whereby the eccentric axis follows a substantially elliptical path rather than a triangular one. The dwell produced by this arrangement varies from about to of a revolution, depending upon the degree of eccentricity of the rod-to-pinion connection.

The original version of my motion is preferred, however, to the above for the reason that in order to secure a lay throw of the proper distance in the modified form, the ring gear must be of as large a diameter as to be unwieldy and diificult to position within the loom.

While this invention is particularly well suited to effect an increase in the speed of operation of the loom, alternatively, it permits the use of larger and heavier shuttles at conventional loom speeds or lower shuttle speeds with less wear on the warp and less vibration resulting from shuttle checking.

It is to be understood that the aforegoing description of my invention is by way of example only and not by way of limitation and that it is capable of modification or variation of detail within the scope of the appended claims.

The following is claimed:

1. A drive for the lay of a mechanical loom comprising a driven crankshaft, a fixed annular gear member encircling said shaft, a second gear member rotatably carried by said shaft internally of said annular member, having a 1:3 gear ratio relative to said annular memher, and meshing therewith, means linking said lay with said second member, the locus of the connection of said linking means with said second member being eccentric with respect to the axis of said second member said locus forming an equilateral triangle having an apex thereof directed toward the connecting point of said lay with said linking means, whereby said lay remains substantially in its back position for approximately one-third of a revolution of said crankshaft.

2. In a beat-up motion for actuating the lay of a mechanical loom, the combination with each of a pair of lay swords supporting the lay for pivotal movement about a horizontal axis and a driven crankshaft having a pair of cranks spaced thereon, of a fixed internally geared ring encircling said shaft at each of the cranks, a pinion rotatably carried by each of said cranks, meshing with the ring gear and having one-third as many teeth as said ring, and a connecting rod having one end thereof eccentrically connected to said pinion so that the eccentric axis has a path of travel substantially in the shape of an equilateral triangle, the other end of the rod being pivotally connected to said lay, the mechanism being so arranged that a straight line drawn through the loci of the pivotal axis of said other end of the rod at the extreme forward and backward positions of the lay bisects one of the angles of said triangle, said one angle having its apex directed toward said rod and lay.

3. A mechanism for connecting the oscillatable lay of a loom to the driven crankshaft thereof comprising a pinion rotatably carried by the crank on said shaft, said pinion carrying a circular disk integral therewith and eccentric with respect thereto, the eccentric axis being so located that it follows a path in the shape of a three-sided epicyclic having slightly convex sides upon rotation of the pinion, a fixed internal gear encircling said crank, and meshing with said pinion, said gear having three times as many teeth as said pinion, and a connecting rod having the crank end thereof encircling said disk and in sliding engagement with the peripheral wall of said disk, the wrist-pin end of said crank being pivotally connected to said lay, the arrangement being such that at one of the cusps of the epicycle, the axes of the disk and pinion lie along a straight line extending through the loci of the pivotal axis of said wrist-pin end at the extreme forward and backward positions of the lay, said one cusp being directed toward said rod.

4. In combination with the lay of a mechanical loom having a frame, means for actuating said lay comprising a driven crankshaft journaled to said frame, a pair of cranks being provided on said shaft, a pinion rotatably carried by each of said cranks, a fixed ring gear meshing with each of said pinions, the ratio of the circumference of the pinions to that of the ring gears being 1:3, a connecting rod connecting said lay to each of said pinions, the locus of the rod-to-pinion connection being eccentric with respect to the axis of revolution of the pinion, the ratio of the radius of eccentricity to the radius of the crank to the length of the connecting rod being substantially 0.15-O.30;l:3.59.5 whereby the eccentric axis moves in a path having substantially the shape equal to an equilateral triangle, the eccentric axis being at the locus of one of the apices of said triangle where said lay is in its extreme forward position.

References Cited in the file of this patent UNITED STATES PATENTS 365,420 Widmer June 28, 1887 1,508,235 Mosley Sept. 9, 1924 1,634,915 Roland July 5, 1927 FOREIGN PATENTS 414,517 Italy Dec. 7, 1946 902,032 France Nov. 20, 1944

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