US3347277A

US3347277A - Vibration isolating support for looms

Info

Publication number: US3347277A
Application number: US496280A
Authority: US
Inventors: Jr James T Gwinn
Original assignee: Lord Corp
Current assignee: Lord Corp
Priority date: 1965-10-15
Filing date: 1965-10-15
Publication date: 1967-10-17
Anticipated expiration: 1984-10-17
Also published as: CH461184A; BE686625A

Description

Oct. 17, 1967 J. T. GWINN, JR 3,347,277

VIBRATION ISOLATING SUPPORT FOR LOOMS Filed Oct. 15, 1963 2 Sheets-Sheet 2 E W N 5 FIG. 6

INVENTOR.

United States Patent 3,347,277 VIBRATION ISOLATING SUPPORT FOR LOOMS James T. Gwinn, Jr., Erie, Pa., assignor to Lord Corporation, Erie, Pa., a corporation of Pennsylvania Filed Oct. 15, 1965, Ser. No. 496,280 9 Claims. (Cl. 139-1) ABSTRACT OF THE DISCLOSURE Vibrations from loom lay and picker mechanism are isolated by suspending the loom by universally swingable tension links, preferably wire cables, which support the loom for free rocking movement about an axis below the center of gravity so that the vibrations originating in the loom and picker mechanism are spent in rocking the loom.

This application is a continuation in part of application Ser. No. 426,224 filed Jan. 18, 1965.

Textile looms have a substantial vibration problem, principally introduced by the lay which packs the weft threads and by the picker mechanism which propels the shuttle. See Patent 2,187,510 and Shock and Vibration Handbook, Harris and Crede, 1961 edition, McGraw- Hill, volume 2, pages 32-6, 32-7. Typically, the lay (an unbalanced reciprocating member weighing some two to five hundred pounds) oscillates at speeds between one hundred and three hundred cycles per minute through a double amplitude of approximately six inches. The line of action of the inertia force due to oscillation of the lay is usually located above (sometimes below) the center of gravity of the loom and results in both fore and aft horizontal and vertical reaction forces at the loom feet (or attachment points to the supporting structure). In addition to the reaction forces due to the lay motion the picker mechanism of the loom generates lateral horizontal and vertical reaction forces. When the loom is rigidly attached to its support, the forces at the atachment points are directly transmitted to the support and in pracice have been the cause of extensive loom and building damage.

This invention isolates the vibration by supporting the loom for friction free rocking about axes crosswise to the lay and picker motions. Thus, the inertia forces of the lay and picker mechanism are counteracted by the inertia force of the rest of the loom. The lay and picker mechanism and loom motions are out of phase and theoretical isolation of the lay and picker mechanism inertia force is 100% if such a system is employed to its full effectiveness.

In a preferred form, the loom is suspended by flexible cables and the axes are chosen so the lay and picker forces act through or near the centers of percussion. This provides a seismic suspension which ideally has no dampnig or elasticity.

In operation, there is a weight or mass shift as the warp threads .are transferred into finished cloth which is periodically removed from the loom, but this shift does not have a large effect upon the vibration isolation.

The low frequency of the lay and picker vibrations (2 to 5 cycles per second) make a resilient suspension impractical. Energy absorption or friction damping structures for restraining motion of the loom transmit the retarding forces to the building. The seismic suspension theoretically achieves 100% isolation and in practice has produced 7090% isolation on a Draper Model X3 loom with the lay operating at 218 cycles per minute. The bare loom weighed 3447 lbs. and had a harness weighing 118 lbs., a warp beam weighing 237 lbs. empty and 779 lbs. full, and a cloth roll weight of 0-120 lbs. The maximum total weight was 4,344 lbs. with a full warp beam and In the drawing, FIG. 1 is a diagrammatic side elevation of a loom, FIG. 2 is a diagrammatic front elevation of a loom, FIG. 3 is a side elevation of a loom suspension, FIG. 4 is a top plan of the portion of the loom suspension shown in FIG. 3, FIG. 5 is an end elevation of one of the front suspension elements, and FIG. 6 is a floor plan of the loom suspension.

In the drawing, the loom is diagrammatically indi cated at 1, typically weighs 4,000 pounds, and typically has an additional load of thread and finished cloth. As the cloth is woven and the finished cloth removed, this additional load continually changes in magnitude and location.

The principal sourceof vibration in the loom is the lay diagrammatically indicated at 2 which is reciprocated fore and aft by a crank 3 at a speed of from one hundred to three hundred strokes per minute. The lay weights from 200 to 500 pounds and the shaking forces it generates are damaging to textile buildings. Since the magnitude of these forces increases as the square of the speed, the effects are becoming more pronounced in modern high speed operation.

Another important source of vibration is the picker mechanism diagrammatically indicated at 4 which is actuated alternately on opposite sides of the loom also at the speed of the crank 3. While the picker mechanism is lighter in weight than the lay, the related accelerations are greater and the resultant vibration is substantial.

To prevent the destructive effects of this vibration, the loom is supported by a structure diagrammatically shown in FIGS. 1 and 2 which in effect utilizes the inertia of the loom to react against the lay and picker mechanisms thereby isolating the vibration. In FIG. 1, in the region of the four corners of the loom are two brackets 6 at the front and two brackets 7 at the rear mounted on the building floor 8. The term floor is used to include other supporting structure. Between the bracket 6 and the front of the loom are flexible steel cables 9 applying to the loom a tension force along dotted lines 10. Between the brackets 7 and the rear of the loom are flexible steel cables 11 applying to the loom a tension force along dotted lines 12. The cables 9 and 11 support the .loom for rotation about an axis extending crosswise of the loom through an instantaneous center of rotation 13. The cables may extend at different angles depending on lay and loom translational and rotational inertia properties and the lays location in the loom. As the lay reciprocates, it exerts a fore and aft inertia force indicated by arrow 15 a distance a above the loom center of gravity 14. When the force 15 passes exactly through the loom center of percussion, the force 15 produces only rocking motion of the loom about axis 13 and there is no transmission of the force 15 to the floor. Because of the continual change in weight of the loom in the course of the weaving, the line of action of the forces 15 due to the lay cannot precisely pass through the loom center of percussion but acceptable results are obtained if the center of rotation 13 is chosen so that the line of action of force 15 is near the center of percussion.

In FIG. 2, which is a front elevation of the loom, the cables 9 apply tension forces to the loom along lines 10 which intersect at point 16 and support the front end of the loom for rotation or rocking movement about an axis transverse to the picker vibration forces indicated by arrow 17. The point 16 is usually at a different distance below the floor 8 than the point 13. If the picker vibration 17 passes exactly through the loom center of percussion, none of the picker vibration is transmitted to the floor.

For perfect isolation of lay vibrations, b (the distance from the line of action of the lay forces to the center of rotation 13) should be equal to T12 a 1+ on where a is the distance from the line of action of the lay forces to the loom center of gravity 14 and r is the centroidal radius of gyration of the loom.

For perfect isolation of the picker vibrations, b (the distance from the line of action 17 of the picker forces to the center of rotation 16) should equal to where a is the distance from the line of action of the picker forces to the loom center of gravity and r is the centroidal radius of gyration of the loom.

Usually the lay and picker forces have lines of action 15 and 17 above the loom center of gravity 14 and the centers of

rotation

13 and 15 are below the loom center of gravity. If either force has a line of action below the loom center of gravity, then the corresponding center of rotation would be above the loom center of gravity. For this case, the cables 9 and 11 would converge upwardly instead of downwardly as illustrated.

While the cables 9 and 11 in FIG. 1 are oriented to be primarily effective for the fore and aft lay vibrations, the cables also allow sidewise motion of the loom and are helpful in isolating the sidewise inertia forces generated by the picker mechanism. Similarly, while the cables 9 in FIG. 2 are oriented to be primarily effective for isolating sidewise vibrations of the picker mechanism, the cables also allow fore and aft motion of the loom which is effective in isolating the lay vibrations. Stated differently, it is not necessary that the cables 9 and 11 have the compound orientation illustrated in FIGS. 1 and 2. Some isolation of the picker vibration is obtained if the cables 9 at the front of the loom do not converge toward the point 16 as illustrated in FIG. 2. While the orientations of FIGS. 1 and 2 are preferred, some isolation is obtained due to the flexibility of the support system using cables 9 and 11 without the illustrated orientation. The cables 9 and 11 are substantially non-stretchable in the length direction but are free to flex in any direction crosswise to the length direction and are universally swingable tension links.

Because the cables 9 and 11 provide a tension support, .a high degree of stability is obtained.

While metal wire cables are preferred for the elements 9, 11 due to the high strength and low internal friction or damping which provides the ideal suspension for a seismic support, chains or hinged links may be substituted for the cables. In the case of the links, the joints should permit swinging lengthwise and crosswise of the loom if both the lay and picker vibrations are to be isolated.

In FIGS. 3 to 6 is shown a mounting system for isolating the lay vibration. This system has two brackets 18 at the front of the loom mounted on the floor in the locations indicated at 19 in FIG. 6 and two brackets 20 at the rear of the loom to be mounted on the floor in the locations indicated at 21 in FIG. 6. The front and rear brackets at each side of the loom are connected by a bar or strut 22 which positions the

brackets

13 and 2% in fixed relation to each other. The struts occupy the positions illustrated at 23 in FIG. 6. Each strut and its associated front and rear brackets comprise an assembly which may be cemented to the building floor to fix their installed location. The struts resist the longitudinal static forces from the brackets so that only the dead Weight of the loom is transmitted through the brackets to the building floor.

Each of the front brackets 18 has a pair of wire cables 24 extending between top and

bottom plates

25 and 26. The top plate 25 is fixed to the bracket 18. The bottom plate 26 underlies and is bolted to one of the front loom feet 27. The rear brackets 20 each have a pair of wire cables 28 extending between top and

bottom plates

29 and 30. The top plate 29 is fixed to the bracket and the bottom plate 30 underlies and is bolted to one of the rear loom feet 31. The cables 24 have a steeper slope than the cables 28 because the center of gravity of the loom is toward the front. In order to keep the loom level, each bottom plate 30 rests on the toe 32a of a stabilizer bracket 32 having knuckles 32b pivoted on pin 32c carried by the knuckle 32d at the upper end of a link 32e. The bracket 32 has a seat 33 for a compression spring 34. The lower end of the spring 34 seats in a member 35 fixed to bracket 20. The link 32 slidably extends through the member 35 and the weight of the loom holds a nut 36 against the underside of the member 35. The position of the loom is adjusted by the nut 36 which raises and lowers the end of the bracket remote from the loom and thereby levels the loom.

The

cables

24 and 23 lie in planes fore and aft of the loom and are focused lengthwise of the loom in the same manner as cables 9 and 11 in FIG. 1. The effect of the

cables

24 and 28 is primarily to cushion the lay forces. However, the cables do have some cushioning effect on the picker forces because of the lateral or sidewise flexibility. The

cables

24 and 28 may also be focused crosswise of the loom in the same manner as the cables 9 in FIG. 2 to introduce additional cushioning of the picker forces.

What is claimed as new is:

1. In a loom having a frame having supporting feet spaced on opposite sides of the frame at the front and rear and above and out of load carrying relation to a floor and having mounted thereon a warp beam, harness, cloth roll and reciprocating l-ay mechanism acting lengthwise of the frame, said lay mechanism having a line of action fore and aft of the frame and to one side of the loom center of gravity, a floor supporting bnacket associated wtih each foot, said bracket having its lower end in load carrying relation to the floor and its upper end above the associated foot, a universally swingable tension link in load carrying relation between the upper end of each bracket and the associated foot, said links converging toward an axis crosswise of the loom and on the side of the loom center of gravity opposite the line of action of the lay mechanism.

2. The loom of claim 1 in which the line of action of the lay mechanism is above the loom center of gravity and the links converge fore and aft of the frame toward a center of rotation below the loom center of gravity and between the front and rear of the frame.

3. The loom of claim 1 in which the frame has mounted thereon picker mechanism with a line of action to one side of the loom center of gravity and crosswire of the frame and the links converge crosswise of the frame toward a center of rotation between the sides of the frame and on the side of the loom center of gravity opposite the line of action of the picker mechanism.

4. The loom of claim 1 in which the line of action of the lay mechanism passes substantially through the center of percussion of the supported loom.

5. In a loom having a frame having supporting feet spaced above and out of load carrying relation to a floor and on opposite sides of the frame at the front and rear and having mounted thereon a warp beam, harness, cloth roll and reciprocating lay and picker mechanism respectively acting lengthwise and crosswise of the frame, said lay and picker mechanism each having a line of action on one side of the loom center of gravity, a supporting bracket associated with each foot, said bracket having its lower end in load carrying relation to the floor and its upper end spaced above the floor, a universally swingable tension link in load carrying relation between the upper end of each bracket and its associated foot, the links at the front and back of the loom converging to a center of rotation on the side of the loom center of gravity opposite the line of action of the lay mechanism and the links at the opposite sides of the loom converging toward a center of rotation on the side of the loom center of gravity opposite the line of action of the picker mechanism.

6. The loom of claim 1 in which the frame has mounted thereon picker mechanism with a line of action above the loom center of gravity and crosswise of the frame and in which the links converge fore and aft of the frame toward a center of rotation below the loom center of gravity and between the front and rear of the frame and also converge crosswise of the frame toward a center of rotation between the sides of the frame and below the loom center of gravity.

7. In a loom having a frame having supporting feet spaced above and out of load carrying relation to a floor on opposite sides of the frame at the front and rear and having mounted thereon a warp beam, harness, cloth roll and reciprocating lay and picker mechanism respectively acting lengthwise and crosswise of the frame and said lay and picker mechanism each having a line of action on one side of the loom center of gravity, a floor supporting bracket associated with each foot, said bracket having its lower end in load carrying relation to the floor and the upper end spaced above the associated foot, a cable in load carrying relation between the upper end of each bracket and the associated foot, the cables at the front and back of the loom converging to a center of rotation on the side of the loom center of gravity opposite the line of action of the lay mechanism and the cables at the opposite sides of the loom converging toward a center of rotation on the side of the loom opposite the line of action of the picker mechanism.

8. The loom of claim 1 in which the line of action of the picker mechanism passes substantially through the center of percussion of the supported loom.

9. The loom of claim 1 in which the links are cables.

References Cited UNITED STATES PATENTS 2,187,510 1/1940 Batchelder 248-21 2,685,425 8/1954 Wallerstein 248-22 X 3,115,323 12/1963 Crandell 248-20 3,160,376 12/1964 Kennedy et a1 139-1 X 3,204,911 9/1965 Lawrence et al 248-358 3,239,207 3/1966 Camossi 248-358 X 3,282,543 11/1966 Engels 248-22 FOREIGN PATENTS 546,004 6/ 1942 Great Britain. 1,272,615 8/ 1961 France.

MERVIN STEIN, Primary Examiner.

J. KEE CHI, Assistant Examiner.

Claims

1. IN A LOOM HAVING A FRAME HAVING SUPPORTING FEET SPACED ON OPPOSITE SIDES OF THE FRAME AT THE FRONT AND REAR AND ABOVE AND OUT OF LOAD CARRYING RELATION TO A FLOOR AND HAVING MOUNTED THEREON A WARP BEAM, HARNESS, CLOTH ROLL AND RECIPROCATING LAY MECHANISM ACTING LENGTHWISE OF THE FRAME, SAID LAY MECHANISM HAVING A LINE OF ACTION FORE AND AFT OF THE FRAME AND TO ONE SIDE OF THE LOOM CENTER OF GRAVITY, A FLOOR SUPPORTING BRACKET ASSOCIATED WITH EACH FOOT, SAID BRACKET HAVING ITS LOWER END IN LOAD CARRYING RELATION OF THE FLOOR AND ITS UPPER END ABOVE THE ASSOCIATED FOOT, A UNIVERSALLY SWINGABLE TENSION LINK IN LOAD CARRYING RELATION BETWEEEN THE UPPER END OF EACH BRACKET AND THE ASSOCIATED FOOT, SAID LINKS CONVERGING TOWARD AN AXIS CROSSWISE OF THE LOOM AND ON THE SIDE OF THE LOOM CENTER OF GRAVITY OPPOSITE THE LINE OF ACTION OF THE LAY MECHANISM.