US3921676A

US3921676A - Warp let-off motion

Info

Publication number: US3921676A
Application number: US366659A
Authority: US
Inventors: Josef Pech; Vladimir Kriz; Zbynek Nespesny
Original assignee: Vyzkumny Ustav Bavlnarsky AS
Current assignee: Vyzkumny Ustav Bavlnarsky AS
Priority date: 1972-06-02
Filing date: 1973-06-04
Publication date: 1975-11-25
Anticipated expiration: 1992-11-25
Also published as: GB1423282A; DE2327326A1; JPS4947655A; AT325534B; ES415455A1; IT988893B; CS200288B1; CH561309A5

Abstract

A warp let-off motion for a weaving machine, having a warp tension sensor responsive to changes in warp tension by varying its position, and a warp beam driven from a machine drive via an eccentric motion, a one-way clutch and a self-locking transmission. The let-off motion includes a pivotally mounted body driven from the weaving machine drive, in said body, there being swingingly mounted on angular lever, one end of the angular lever being connected to the warp, tension sensor, and the other end being swingingly connected to a slide means mounted on said body for sliding perpendicularly to the axis of pivotal mounting of the body. The slide means is connected by a connecting rod with a swinging arm of the one-way clutch.

Description

United States Patent Pech et al. 1 5] Nov. 25, 1975 [54] WARP LET-OFF MOTION 2.920.659 1/1960 Pfarrwaller 139/110 .r. 2.946.352 7/1960 M K .1 139/110 [75] mentors: g f f y g Km; Zbynek 3.122.172 2/1964 111111623 2: 139/110 espesny, a 0 mo, Czechoslovakia Primarv Emminer James Kee Chi [73] Assignee: Vyzkumny ustav bavlnarsky, Usti I nad Orlici. Czechoslovakia ABSTRACT 99 [-7] Filed June 1973 A warp let-off motion for a weaving'machine, having a [21] Appl. No.: 366,659 warp tension sensor responsive to changes in warp tension by varying its position, and a warp beam driven from a machine drive via an eccentric motion, [30] Forelgn Apphcatlon pnmy Data a one-way clutch and a self-locking transmission. The June 2. 1972 Czechoslovakia 3813-72 let off motion includes a pivotal), mounted body 7 driven from the weaving machine drive, in said body, [5.] US. Cl .7 139/110 there being swingingly mounted on angular lever, one [51] Illl. Cl. D031) 49/06 end f the angular lever i g connected to the warp [58] Field of Search 139/110, 109, 104, 103, tension Sensor, and the other end being swingingly. 139/100 97; 66/86 A; connected to a slide means mounted on said body for sliding perpendicularly to the axis of pivotal mounting 156] References of the body. The slide means is connected by a con- UNITED STATES PATENTS necting rod with a swinging arm of the one-way 2.635.646 4/1953 Payne 139/110 u 2.819.734 1/1958 Pfarrwaller 1 139/110 2.878.839 3/1959 Clentimack 139/110 7 Clam, 5 Drawing Flgures US. Patent Nov. 25, 1975 Sheet10f4 3,921,676

U.S. Patent Nov. 25, 1975 Sheet 2 of 4 U.S. Patent Nov. 25, 1975 Sheet3of4 3,921,676

US. Patent Nov. 25, 1975 Sheet4 Of4 3,921,676

FIG. 5

This invention relates to a motion for letting off warp from a warp beam, said motion being controlled by the warp tension of the weaving machine.

A motion for letting off warp from the warp beam is known wherein the torsional moment for driving the warp beam is transmitted to an eccentric means with pivotally mounted pull rod. To this pull rod there are swingingly connected two pull rods: a control rod and a main rod. The control rod, which permits the rod of the eccentric means to swing, is adjustably disposed. The main rod connects the rod of the eccentric means with a one-way clutch which transfers the main rod movement with a gradual rotary movement whereby to drive the warp beam. The position of the swing direction of the eccentric .rod varies according to the adjusted position of the control rod, andaccordingly the swing length, by means of which the main rod acts on the one-way clutch, alsovaries. The'position of the control rod is controlled by varying the position of a warp tension sensor. The disadvantages of this motion consist particularly in a considerably complicated structure, and a low sensitivity to the variation in warp tension because the variation in position of the control rod requires a relatively great force and consequently a relatively great energy from the warp tension sensor.

The motion, according to the present invention, has as an object the elimination of the above mentioned disadvantages. In accordance with the invention, there is provided a pivotally mounted body, driven from the weaving machine drive, in the interior of which an angular lever is swingingly mounted, one end of the angular lever being connected to the warp tension sensor and the other end of the angular lever beingswingingly connected to a slide means mounted slidably in a direction perpendicular to the axis of pivotal mounting of the body. The slide, means is connected e.g., by .means of a connecting rod with a swinging arm of a one-way clutch connected by a transmission with the warp beam of the weaving machine. I

The principal advantages of the motion, according to the invention, are a great sensitivity to thewarp tension variation in the course of weaving, and the fact that for varying the letting off velocity only little force or energy from the warp tensionsensor suffices. Further advantages of the motion are a relative simplicity, good service reliability, and long useful life.

An illustrative embodiment of the motion, according to the invention, is shown in the accompanying drawings, in which:

FIG. 1 is front view of the motion of the invention for letting off warp from a warp beam of a weaving machine;

FIG. 2 is a side view of the let-off motion shown in FIG. I;

FIG. 3 is a side view, partially insection, of the let-off motion; 1 I

FIG. 4 is a detail view of an one-way clutch of the letoff motion, and

FIG. 5 is an enlarged detailed view of mechanism which is somewhat schematically shown at the lower left of FIG. 3 of the drawing, certain of the parts being shown in section and others of the parts being shown in elevation.

On the frame 1 of a weaving machine there is pivotally mounted a warp beam 2. The warp 3, wound on the warp beam 2, is conducted via a back-rest roller 4 to two-similar paralleltension levers 5 which tension the warp 3. The tensioning forceof springs 6 is adjusted by set screws 7. The back-rest roller 4 on the levers 5 biased by springs 6 also functions as a warp tension sensor reacting by varying itsposition to variations in tension of the warp 3.

The let-off motion of the loom or weaving machine is used for driving the warp beam 2. Such let-off motion is formed by body 9 pivotally mounted in the housing 10 upon the frame 1 of the machine. An angular lever 11 is swingingly mounted in the interior of the body 9 on a pivot pin 12, one end of said leverll closely cooperating with the warp tension sensor. In the illustrative embodiment such one end of the angular lever 11 is swingingly connected to a pull rod 13. Rod 13 is swingingly and non-rotatably connected e.g., by a pin 14 with a bushing 15 mounted slidably in. an axial direction in spring 16 into contact with the arm 8 of the tension lever 5 e.g., via a swingingly mounted push button-l7.

The other end of the angular lever 11 is swingingly connected to a slide means 18 which is mounted for sliding in a direction perpendicular to the axis 20 of pivotal mounting of the body 9 in the guide 19. The slide means 18 can change its eccentricity in the guide 19 from maximum at the end of the guide 19 of the body 9 to zero at the beginning of the guide 19 in the axis 20 of the body 9, as shown in FIGS. 3 and 4.

The body 9 of the motion is further connected e.g., via a bevel gear set 21, 22, to the gear 22 being affixed to a shaft 22, which is connected to the drive of the weaving machine (not shown).

A connecting rod 23 is pivotally connected to the slide means 18 for transmitting the rotational movement from the machine drive to the warp beam 2. The connecting rod 23 is swingingly connected to an arm 25 of a one-way clutch 24. Clutch 24 is connected with the warp beam 2 via a worm 38 on the shaft 26 of the clutch 24 and a worm wheel 39 on the shaft 40 of the warp beam 2.

It is advantageous to use as one-way clutch 24 a oneway clutch with rolling contact elements. In the illustrative embodiment shown in FIG. 4, the clutch has a sleeve or drum 27 on which there is arranged an arm 25 for connection with the connecting rod 23, the drum 27 being pivotally mounted on the hub 28 of the clutch. In the hub 28 there are formed wedge seats 29 for the rolling-contact elements 30, which may be spring loaded rollers, as shown. To the shaft 26 of the clutch 24, there is secured a ring or disc 31, disc 31 being provided with lugs 32 which can rotate in the hub 28 of the clutch 24. Pull rods 33 are slidably mounted in the hub 28 between

stops

35 and 36 which are disposed tangentially to the ring 31, pull rods 33 having the recesses 34 which receive lugs 32 on the ring 31. In the position shown in FIG. 4, in which the pull rods engage the first stops 35, the pull rods 33 prevent the rolling-contact elements 30 from driving engagement with their seats. In the second position in which the rods .33 engage the second stops 36, the elements 30 transmit the rotation of the hub 28 of the clutch 24 in one direction to the shaft 26 of the clutch 24 via the disc 31, the one-way clutch 24, thus functioning in its normal manner.

On the prolongation of the shaft 26 of the clutch 24 there is mounted a handwheel 37 for the manual rotation of the warp beam 2. The one-way clutch 24 permits such normal rotation of the warp beam in the direction of its normal function. During the angular rotation of the warp beam in the direction opposite to the normal function, the pull rods 33 in the hub 28 of the clutch 24 disable the one-way clutch 24.

FIG. 5, which is in an enlarged constructional view of the mechanism shown schematically at the lower left of FIG. 3, shows the shaft 22 upon which bevel 22 is mounted, the cavity in the slide means 18 and the rounded end 44 of the angle level 11 which is receded in said cavity. It will be understood that FIG. 4 is a view of the front end 45 of the body 9, and that in FIG. 5 only the part 46 of the slide means 18intended for the pivotal mounting of the connecting rod 23 is shown in section.

In the course of weaving, the required tension of the warp 3 is adjusted by adjusting the tension of springs 6 by set screws 7. Further, adjustment of warp tension, if necessary, is effected by use of the handwheel 37. When the tension does not vary, i.e., the rate of letting off of the warp 3 from the warp beam 2 is equal to the rate of withdrawal of the warp 3, the eccentric position of the slide means 18 does not vary and corresponds to the length of the warp 3 withdrawn during one revolution of the machine. The rotational movement of the slide means 18, caused by rotating the body 9 by the weaving machine drive, is transformed by the connecting rod 23 in a swinging movement of the arm 25 of the one-way clutch 24. The angular displacement of the hub 28 of the clutch 24' is transmitted via the shaft 26 of the clutch, worm 38 and worm wheel 39 to the shaft 40 of the warp beam 2. If the tension of the warp 3 rises, i.e., the rate of letting off warp 3 issmaller than the rate of warp 3 withdrawn, the position of the tension lever 5 changes and its arm 8, by varying the position of the push button 17, increases the eccentricity of the slide means 18 which results in increasing the rate of letting off warp 3 and the tension of the warp is restored to the desired value.

The warp let-off motion of the invention is especially applicable in the continuous withdrawal of warp, e.g., in a wave-type weaving machine where the back-seat roller does not substantially vary its position during normal operation. In weaving machines with a greater change in warp tension it is preferred to incorporate a yieldable means such as a spring between the push button 17 and the arm 8 of the tension lever -5, for example, so that only the intermediate position of the tension lever 5 causes a variation in the eccentric position of the slide means 18.

Although the invention is illustrated and described with reference to a plurality of preferred embodiments thereof, it is to be expressly understood that it is in no way limited to the disclosure of such a plurality of preferred embodiments, but is capable of numerous modifications within the scope of the appended claims.

What is claimed is:

1. In a weaving machine, having a machine drive, a

off motion including means for driving the warp beam.

from the machine drive via an eccentric motion, oneway clutch and a self-locking transmission, the improved warp let-off motion which comprises a pivotally mounted body driven from the weaving machine drive, a connecting means movably mounted in said body, one end of the movable connecting means being connected to the warp tension sensor, a slide means mounted in the body for sliding perpendicularly to the axis of pivotal mounting of the body, the other end of the connecting means being pivotally connected to the slide means; the one-way clutch having a swinging arm and a connecting rod, connecting the slide means with the swinging arm of the one-way clutch.

2. The let-off motion of claim 1, wherein the connecting means is a lever, and comprising pivot means housing mounted axially within the body for rotation therewith and axial reciprocation with respect thereto,

a pull rod pivotally attached to said one end of the lever, means pivotally attaching the pull rod to the housing, a spring opposing axially inward movement of the housing with respect to the body, and means connecting the warp tension sensor to the pull rod in opposition to the spring. a

5. A let-off motion, according to claim 1, wherein the one-way coupling is mounted on a clutch shaft, a disc with spaced lugs attached to the clutch shaft, the clutch having a hub which is pivotally mounted on the clutch shaft, and pull rods mounted in the hub of the clutch tangent and connected to the disc to said lugs so as to be reciprocatedthereby, said pull rods selectively dis abling the clutch from its normal one-way action.

6. A let-off motion, according to claim 5, wherein the clutch has wedge-shaped seats, each having an apex in the hub, a drum coaxial of the clutch shaft, surrounding the hub, and a rolling clutch element in each seat the radially outer ends of the pull rods extending into the respective seats and selectively restraining the rolling. I

elements from movements toward the apex of the respective seat.

7. A let-off motion, according to claim 6, comprising first and second stops disposed longitudinally of the respective pull rods to define the limits of movement of the pull rods between a first position in which the pull rods restrict the rolling elements from movement toward the apex of the respective seat and a second position in which the pull rods are retracted to permit movement of the rolling elements toward said apices of the seats.

Claims

1. In a weaving machine, having a machine drive, a warp tension sensor responsive to the changes in warp tension by varying its position, a warp and a warp let-off motion including means for driving the warp beam from the machine drive via an eccentric motion, one-way clutch and a self-locking transmission, the improved warp let-off motion which comprises a pivotally mounted body driven from the weaving machine drive, a connecting means movably mounted in said body, one end of the movable connecting means being connected to the warp tension sensor, a slide means mounted in the body for sliding perpendicularly to the axis of pivotal mounting of the body, the other end of the connecting means being pivotally connected to the slide means; the one-wAy clutch having a swinging arm and a connecting rod, connecting the slide means with the swinging arm of the one-way clutch.

2. The let-off motion of claim 1, wherein the connecting means is a lever, and comprising pivot means mounting the lever in said body.

3. The let-off motion of claim 2, wherein the lever is an angular lever having two angularly disposed arms, and the pivot means is disposed at the junction of such two arms of the angular lever.

4. The let-off motion of claim 2, wherein the connection of said one end of the connecting means to the warp tension sensor is effected by means including a housing mounted axially within the body for rotation therewith and axial reciprocation with respect thereto, a pull rod pivotally attached to said one end of the lever, means pivotally attaching the pull rod to the housing, a spring opposing axially inward movement of the housing with respect to the body, and means connecting the warp tension sensor to the pull rod in opposition to the spring.

5. A let-off motion, according to claim 1, wherein the one-way coupling is mounted on a clutch shaft, a disc with spaced lugs attached to the clutch shaft, the clutch having a hub which is pivotally mounted on the clutch shaft, and pull rods mounted in the hub of the clutch tangent and connected to the disc to said lugs so as to be reciprocated thereby, said pull rods selectively disabling the clutch from its normal one-way action.

6. A let-off motion, according to claim 5, wherein the clutch has wedge-shaped seats, each having an apex in the hub, a drum coaxial of the clutch shaft, surrounding the hub, and a rolling clutch element in each seat the radially outer ends of the pull rods extending into the respective seats and selectively restraining the rolling elements from movements toward the apex of the respective seat.