US3347502A

US3347502A - Mounting system for looms and the like

Info

Publication number: US3347502A
Application number: US426224A
Authority: US
Inventors: Jr James T Gwinn
Original assignee: Lord Corp
Current assignee: Lord Corp
Priority date: 1965-01-18
Filing date: 1965-01-18
Publication date: 1967-10-17
Anticipated expiration: 1984-10-17

Description

Oct. 17, 1967 J. T.'GWINN, JR 3,347,502

MOUNTING SYSTEM FOR LOOMS AND THE LIKE Filed Jan. 18, 1965 5 Sheets-Sheet l Oct. 17, 1967 w J 3,347,502

MOUNTING SYSTEM FOR LOOMS AND THE LIKE- Filed Jan. 18, 1965 5 Sheets$heet 2 W Li INVENTOR. N/ /,7/

W gm Timmy,

0 1967 J. T. GWINN, JR

MOUNTING SYSTEM FOR LOOMS AND THE LIKE 5 Sheets-Sheet 1' Filed Jan. 18, 1965 5 7 55 PEG/3 United States Patent 3,347,502 MOUNTING SYSTEM FOR LOOMS AND THE LIKE James T. Gwinn, In, Erie, Pa., assignor to Lord Corporation, a corporation of Pennsylvania Filed Jan. 18, 1965, Ser. No. 426,224 22 Claims. (Cl. 248-22) Textile looms have a substantial vibration problem, principally introduced by the lay which packs the weft threads. 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 the center of gravity of the loom and results in both horizontal and vertical reaction forces at the loorn feet (or attachment points to the supporting structure). When the loom is rigidly attached to its support, the forces at the attachment points are directly transmitted to the support and in practice have been the cause of extensive loom and building damage. This invention isolates the forces due to lay motion from the support by allowing the loom to move. Thus, the inertia force of the lay is counteracted by the inertia force of the rest of the loom. The lay and loom motions are out of phase and theoretical isolation of the lay inertia force is 100% if such a system is employed to its full effectiveness.

In the drawing, FIG. 1 is a diagrammatic view of a loom, FIG. 2 is an enlarged View of one of the supports, FIG. 3 is a section on line 3-3 of FIG. 2, FIG. 4 is a section on line 44 of FIG. 2, FIGS. 5, 6, 7 and 8 are diagrammatic views of modifications, FIG. 9 is a perspective of a roller for substitution in FIGS. 1-4, FIGS. 10, 11 and 12 are diagrams illustrating the operation, and FIG. 13 is a diagrammatic view of another modification.

In the drawing, the loom is diagrammatically indicated at 1, typically weighs 4000 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 source of vibration in the loom is the lay 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 weighs 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.

To prevent the destructive effects of this vibration, the loom is supported by a supporting structure which in effect utilizes the inertia of the loom to isolate the vibration. One type of supporting structure has a sheet metal plate 4 cemented to the floor. The purpose of the plate is to locate brackets fixed to opposite ends of the plate in fixed relation to feet 6 at opposite ends of the loom side frames. The brackets 5 and feet 6 have

surfaces

7, 8, plane or of any suitable curvature, approximately perpendicular to center lines 9 passing through a point 19. The point It) lies on an axis which is below the center of gravity 11 of the loom which is intermediate this axis and the line of action 12 of the sum of the forces acting on the lay assembly. The point 10' and the line of action 12 are always on opposite sides of the loom center of gravity 11. Thus, the point 10 is below the center of gravity 11 when line of action 12 is above the center of gravity and ideally the location of the point 10 is such that the line of action of the lay indicated by arrow 12 passes through the center of percussion of the loom with reference to the point 10. Under these conditions of motion constraint, the force generated by the lay produces no tangential reaction on the support. Because of the continual change in weight of the loom in the course of the weaving, the line of action of the forces due to the lay cannot precisely pass through the loom center of percussion but acceptable results are obtained if the point 10 is chosen so that the line of action is near the center of percussion.

In order to prevent transmission of vibration, friction should be minimized. This is accomplished by the roller 13 between the

surfaces

7, 8. The

surfaces

7, 8 are shown as plane but may be curved. For the small motions of the loom about the point 10* which amount to one-fourth inch or less at the

surfaces

7, 8, the surfaces are practically equivalent to arcs of circles centered at 10 and at the same time have a centering effect stably supporting the loom in an upright position. Rocking of the loom in either direction from a central position causes a lifting of the loom providing a restoring force tending to return the loorn to the central position. If the

surfaces

7, 8 were true arcs of circles centered at 10, the loom would be unstable and would not remain in its central position because the center of gravity is above point 10.

While the rollers 13 may bear directly on the

surfaces

7, 8,

flexible straps

14, 15 may alternatively be interposed between the roll and the surfaces. The straps 14 are fixed at one end to a pin 16 on the foot 6 and extend down along surface 8 beneath the roller 13 and up along surface 7 to a pin 17 slidable in a slot 18 in the bracket 5 and adjusted by a tension screw 19. The straps 15 are fixed at one end to a pin 20 fixed in foot 6 and extend up along surface 8 over the top of the roller 13 and down along surface 7 to a pin 21 having opposite ends slidable in slots 22 in the bracket 5 and adjusted by a tension screw 23. With this construction, the roller 13 is effectively trapped between the

straps

14 and 15 and yet is free to roll along the

surfaces

7, 8 in order to accommodate the rocking of the loom as a whole about the point 19. For a typical loom, the motion of the loom at the

surfaces

7, 8 would be of the order of one-fourth inch. This motion does not interfere with the operation of the loom.

The formula locating the center of rotation 10 in order that the line of action of the forces due to the lay indicated by the arrow 12. may pass through the loom center of percussions is where b is the distance from the line of action 12 to the center of rotation 10, a is the distance from the line of action 12 to the loom center of gravity, and r is the radius of gyration of the loom about the center of gravity.

Instead of the supports illustrated, kinematic equivalents may be substituted as shown diagrammatically in FIGS. 5, 6, 7, 8 and 13. FIG. 5 substitutes simple links 24 hav ing lower ends pivoted at 25 corresponding to the center of rotation 10. The upper ends of the links are pivoted to the loom at points 26 corresponding to the rollers 13. Springs 27 between the loom and the floor provide stability. The links 24 permit the same kind of motion as the rollers 13 and associated

structure

5, 6, 7, 8.

In FIG. 6,

elastomeric shear sandwiches

28, 29, 30 are arranged between the brackets 5 and feet 6. The body of elastomer 29 is bonded to the

plates

28, 30 which are respectively fixed to the brackets 5 and feet 6. Under load, the elastomer shears providing the same movement as the rollers 13. The elastomer introduces additional force transmission to the support.

In FIG. 7, short links 31 are arranged between floor brackets 32 and the corners of the loom. The links 31 are focused toward point 33 corresponding to the center of rotation 16. In small motions, the links 31 are equivalent to the rollers 13 and associated

surfaces

6, 7. The short links 31 provide an inherently stable support, and eliminate the need for helper springs 27 shown in FIG. 5.

In FIG. 8 fiexures (flexible straps) 34 are arranged between floor brackets 35 and the corners of the loom. The straps 34 are rigid lengthwise and soft or flexible crosswise thereby providing the same kind of support as the links 31.

In FIG. 13, split rollers 55 are journaled in sockets 56 in the corners of the loom =1 and mating split rollers 57 are journaled in floor pockets 58.

Flat surfaces

59, 60 of the rollers are in sliding engagement and support the loorn for rocking about point 10 so the line of action of the lay indicated by arrow 12 passes through the center, of percussion. Rocking of the rollers in the sockets maintains alignment of the

surfaces

59, 60. Either of the

rollers

55 or 57 may be fixed, in which case the rocking of the free rollers maintains the alignment of the surfaces 59, 60'.

The roller 13a of FIG. 9 may be substituted for the roller 13 in the structure of FIGS. 1 to 4 inclusive. The roller 13a has grooves 131), 13c for cables 14a and 15a. The cables 14a are equivalent to the straps 14 and are secured at opposite ends to the

pins

16 and 17. The cables 15a are equivalent to the straps 15 and are secured at opposite ends to the

pins

20 and 21. With this construction, the rollers 13a bear directly on the

surfaces

7 and 8 and do not crush the cables 14a, 15a.

FIGS. 10, l1 and 12 are diagrams illustrating the operation. In FIG. 10, a body 36 is subject to a force along line 37 from a connecting rod 38 having a driver 39 mounted on an external supporting structure 40. The line of action of the force passes above the center of gravity 41 of the body 36.

In FIG. 11, a connecting rod 42., driven by a crank 43 mounted on a body 44, reciprocates an unbalanced mass 45 along guides 46 centered on a line of action 47, passing above the center of gravity 48 of the body 44.

In FIG. 12, which may be considered as a general form of each 'of the previously described constructions, a reciprocating force indicated by arrow 49 acting along line 50 which is a distance a from the center of gravity 51 of the body 52. The body 52 has a centroidal radius of gyration of magnitude indicated by the line I. If the body 52 were rigidly attached to a supporting structure, the unbalanced force 49 would cause reaction forces. To prevent these unwanted reaction forces on the supporting structure, the body 52 is constrained (e.g. by the previously described structure) to rotate about point 54 a distance b from the line of action 50 of the unbalanced forces 49. When the distance b is equal to the line of action 50 passes through the body center of percussion 55 and the point 54 is the center of rotation of the body 52. With such a construction, there are no tangential reaction forces on the supporting structure even though the angular momentum of the body 52 is changed by the action of the force 49. If the force 49 originates externally of the body 52 as in FIG. 10, the motion of the body 52 is in phase with the force 49. If the force 49 originates internally of the body 52 as in FIGS. 1-9 and 11, the motion of the body 52 is out of phase with the force 49. In either case, the effect of the unbalanced force 4-9 is to rotate the body 52 about the center of rotation 54.

The unbalanced force 49 may be of a shock or vibratory nature.

The flexible straps 14, 15 and the equivalent cables 14a, 15a are in the form of oppositely facing loops embracing the associated roller with the ends of the loops anchored respectively to the foot and its associated bracket.

What is claimed as new is:

1. A loom having a lay reciprocated in a generally horizontal direction above the center of gravity of the loom, and means for supporting the loom for free rocking movement about an axis below the center of gravity of the loom and crosswisev to the direction of reciprocation of the 4 lay, said axis being chosen so the sum of the forces acting on the loom are substantially through the center of percussion of the loom.

2. A loorn having a lay reciprocated in a generally horizontal direction above the center of gravity of the loom, and means for supporting the loom for free rocking movement about an axis below the center of gravity of the loom, said axis being in a plane containing the center of gravity and at a perpendicular distance below theline of action of the forces acting on the loom substantially equal to where a is the distance from the forces acting on the loom t0 the center of gravity of the loom and r is the centroidal radius of gyration of the loom.

3. A loom having lay reciprocated fore and aft above the center of gravity of the loom, fore and aft feet on the loom each associated with a supporting bracket, each foot and its associated bracket having spaced surfaces presented toward each other, a roller between and engaging said surfaces, said surfaces being substantially normal to center planes passing through said rollers and intersecting on an axis below said center of gravity and crosswise of the direction of reciprocation of the lay.

4. A loom having a lay reciprocated fore and aft above the center of gravity of the loom, fore and aft feet on the loom each associated with a supporting bracket, each foot and its associated bracket having spaced surfaces present-7 ed toward each other, a roller between and engaging said surfaces, said surfaces being substantially normal to center planes passing through said rollers and intersecting on an axis below said center of gravity and crosswise of the direction of reciprocation of the lay, said point being chosen so the line of action of the forces on the loom passes.

substantially through the center of percussion of the loom.

5. A loom having a lay reciprocated fore and aft above the center of gravity of the loom, fore and aft feet on the loom each associated with a supporting bracket, each foot and its associated bracket having spaced surfaces presented toward each other, a roller between and engaging said surfaces, said surfaces being substantially normal to center planes passing through said rollers and intersecting on an axis below said center of gravity, said axis being in i a plane containing the center of gravity and at a perpendicular distance below the line of action of the forces acting on the loom substantially equal to where a is the distance from the forces acting on the loom to the center of gravity of the loom and r is the centroidal radius of gyration of the loom.

6. A loom having a lay reciprocated fore and aft above the center of gravity of the loorn, supporting means fore and aft of the loom and comprising inclined surfaces and rollers associated in load carrying relation, the surfaces being substantially normal to center planes passing through said rollers and intersecting on an axis below said center of gravity and crosswise of the direction of reciprocation of the lay.

7. A loom having a lay reciprocated fore and aft above the center of gravity of the loom, supporting means fore and aft of the loom and comprising inclined surfaces and rollers associated in load carrying relation, the surfaces being substantially normal to center planes passing through rollers associated in load carrying relation, the surfaces equal to where a is the distance from the forces acting on the loom to the center of gravity of the loom and r is the centroidal radius of gyration of the loom.

9. A loom having a lay reciprocated fore and aft above the center of gravity of the 100m, supporting means fore and aft of the loom and comprising inclined surfaces downwardly diverging from each other and rollers associated in load carrying relation between said surfaces, the surfaces being substantially normal to center planes passing through said rollers and intersecting on an axis below said center of gravity and crosswise of the direction of reciprocation of the lay, said axis being chosen so the line of action of the forces on the loom passes substantially through the center of percussion of the loom.

10. A loom having a lay reciprocated fore and aft above the center of gravity of the loom, supporting means fore and aft of the loom and comprising inclined surfaces downwardly diverging from each other and rollers associated in load carrying relation between said surfaces, the surfaces being substantially normal to center planes passing through said rollers and intersecting on an axis below said center of gravity, said axis lying in a plane containing the center of gravity and at a perpendicular distance below the line of action of the forces acting on the loom substantially equal to where a is the distance from the forces acting on the loom to the center of gravity of the 100m, and r is the centriodal radius of gyration of the loom.

11. A loom having a lay reciprocated fore and aft above the center of gravity of the loom, fore and aft feet on the loom, each associated with a supporting bracket, each foot and its associated bracket having spaced surfaces presented toward each other, a body of elastomer between and fixed to said surfaces, said surfaces being substantially normal to center planes converging downwardly and intersecting on an axis below said center of gravity and crosswise of the direction of reciprocation of the lay.

12. A loom having a lay reciprocated 'fore and aft above the center of gravity of the 100m, fore and aft feet on the loom, each associated with a supporting bracket, each foot and its associated bracket having spaced surfaces presented toward each other, a body of elastomer between and fixed to said surfaces, said surfaces being substantially normal to center planes converging downwardly and intersecting on an axis below said center of gravity and crosswise of the direction of reciprocation of the lay, said axis being chosen so that the line of action of the forces acting on the loom passes substantially through the center of percussion of the loom.

13. A loom having a lay reciprocated fore and aft above the center of gravity of the loom, fore and aft feet on the loom, each associated with a supporting bracket, each foot and its associated bracket having spaced surfaces presented toward each other, a body of elastomer between and fixed to said surfaces, said surfaces being substantially normal to center planes converging downwardly and intersecting on an axis below said center f gravity, said axis lying in a plane containing the center of 5 gravity and at a perpendicular distance below the line of action of the forces acting on the loom substantially equal to where a is the distance from the forces acting on the loom to the center of gravity of the loom, and r is the centriodal radius of gyration of the loom.

14. The structure of claim '1 in which the means c0m prises a supporting structure, and links pivoted to the loom and to the supporting structure and converging toward said axis.

15. The structure of claim 2 in which the means comprises a supporting structure, and links pivoted to the loom and to the supporting structure and converging toward and axis.

16. The structure of claim 2 having in addition spring means between said supporting structure and the loom resiliently resisting movement of the loom from a central position.

17. The structure of claim 16 having in addition spring means between said supporting structure and the loom resiliently resisting movement of the loom from a central position.

13. The structure of claim 17 having in addition spring means between said supporting structure and the loom resiliently resisting movement of the loom from a central position.

19, The structure of claim 1 in which the means comprises a supporting structure and flexures connected to the loom and to the supporting structure and converging toward said axis.

20. The structure of claim 2 in which the means comprises a supporting structure, and flexures connected to the loom and to the supporting structure and converging toward said axis.

21. The structure of claim 1 in which the means comprises a supporting structure and sliding surfaces substantially perpendicular to planes converging toward said axis.

22. The structure of claim 2 in which the means comprises -a supporting structure and sliding surfaces substantially perpendicular to planes converging toward saiq axis.

References Cited UNITED STATES PATENTS 1,309,759 7/ 1919 Knowlton 24820 X 2,414,506 1/ 1947 Bowen 248-20 2,641,425 6/1953 Ostberg 248358 X 2,978,213 4/1961 Kass 24820 3,160,376 12/1964 Kennedy et al. 248-22 FOREIGN PATENTS 8/1961 France.

Claims

1. A LOOM HAVING A LAY RECIPROCATED IN A GENERALLY HORIZONTAL DIRECTION ABOVE THE CENTER OF GRAVITY OF THE LOOM, AND MEANS FOR SUPPORTING THE LOOM FOR FREE ROCKING MOVEMENT ABOUT AN AXIS BELOW THE CENTER OF GRAVITY OF THE LOOM AND CROSSWISE TO THE DIRECTION OF RECIPROCATION OF THE LAY, SAID AXIS BEING CHOSEN SO THE SUM OF THE FORCES ACTING ON THE LOOM ARE SUBSTANTIALLY THROUGH THE CENTER OF PERCUSSION OF THE LOOM.