US3927699A

US3927699A - Weft carrier control apparatus

Info

Publication number: US3927699A
Application number: US518651A
Authority: US
Inventors: Richard Louis Volpe
Original assignee: Rockwell International Corp
Current assignee: Draper Corp
Priority date: 1974-10-29
Filing date: 1974-10-29
Publication date: 1975-12-23
Anticipated expiration: 1992-12-23
Also published as: CA1025327A; JPS5164065A; FR2289650A1; ES442185A1; IT1041540B; CH595488A5; DE2540265A1

Abstract

An improved control apparatus for controlling actuation of the gripper finger of a weft extending carrier in a shuttleless loom of the gripper type. The apparatus being adapted to control actuation of the gripper finger to release the weft which was held thereby while being drawn through the shed and to prevent its actuation during the carrier''s movement toward the shed to receive the next pick of weft.

Description

US. Patent Dec. 23, 1975 Sheet 1 of2 3,927,699

US. Patent Dec. 23, 1975 Sheet 2 of 2 3,927,699

WEF'I CARRIER CONTROL APPARATUS BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to shuttleless looms of the gripper or single pick insertion type in which weft yarn drawn from a stationary source is inserted as individual picks into separate sheds of warp threads. In particular the invention pertains to a control device effective upon the weft extending carrier for controlling actualion of the carrier's gripper finger which is adapted to grip the weft as it is extended through the shed to complete a single pick.

2. Description of the Prior Art In shuttleless looms to which the instant invention is applicable each pick of weft is inserted by two reciprocating carrier members disposed in opposed relation and which are fixed on the free ends of flexible tapes that are caused to be wrapped about and extended from oscillating wheel members at each side of the loom. One of these carriers is commonly referred to as the inserting carrier and the other as the weft receiving or extending carrier.

In shuttleless looms of the single pick insertion type the weft yarn remains threaded through an eyelet in the rear wall of the inserting carrier and extends in one direction to its source of supply and in the other direction to the selvage or fabric edge.

To form single picks the weft yarn must be clamped, held, then cut adjacent the shed after the inserting carrier is withdrawn from the latter. In preparation for the following pick, the weft yarn is positioned in such a manner as to be caught by a clamping element in the forward wall of the inserting carrier prior to the latters entrance into the shed. The clamped yarn is then released and that portion extending between the front and rear walls of the inserting carrier is properly positioned for positive transfer to the extending carrier. The extending carrier grips the weft adjacent its cut end by means of a gripping finger pivotably mounted intermediate its ends within said carrier. This gripping finger extends within the carrier for a substantial portion of the longitudinal length of the latter and includes a biasing means for continually urging the leading end thereof into a groove of conforming configuration formed in the hooked leading end of the carrier. This biasing means is in the form of a coil spring one end of which seats against an inner rear vertical wall of the carrier and the opposite end is caused to bear against the finger immediately adjacent to its trailing end. This trailing end is in the form of an integral and laterally extending lip which is continually urged forwardly by the coil spring causing a portion thereof to protrude beyond the'forward side of the carrier.

As the carrier is being withdrawn from the shed while extending a pick of wefi thereacross, the protruding lip on the carrier is caused to contact a fixed member that depresses the lip inwardly causing at the same time the release of the gripped end of weft by pivoting the leading end of the finger out of the groove in the carriers hooked leading end.

This means of releasing the extending carriers grip on the weft has performed satisfactorily; however, the fixed member which is effective in pivoting the finger during withdrawal of the carrier from the shed is also effective in pivoting the finger as the carrier is caused to move toward the shed to repeat the cycle of receiving and extending the next pick of weft. This means of actuating the gripper finger on both the withdrawn and insertion movement of the extending carrier causes what is considered premature life expectancy of said carrier. Repeated compression and relaxing of the coil spring for effecting pivotal movement of the carriers gripper finger necessitates frequent replacement of these springs due to fatigue failure which of course is accomplished by excessive loom down time and production loss while making the necessary repairs and replacement.

The weft carrier control apparatus according to the present invention provides a means which alleviates the above condition substantially by causing the carriers gripper finger to be actuated only once during each picking cycle rather than twice as is prevalent with known devices of the prior art.

SUMMARY OF THE INVENTION The improved control apparatus for controlling actuation of the gripper finger of a weft extending carrier includes a cam member mounted adjacent to the edge of the fabric and disposed so as to engage the forwardly extending lip of the carriers gripper finger during withdrawal of the carrier from the shed. The gripper finger at this time is pivoted and releases the weft yarn it was drawing through the shed.

The cam member is spring biased in a downwardly direction as well as in a lateral direction which continually urges its camrning surface to that position to be engaged by the lip of the gripper finger. The leading end portion of the forwardly extending lip of the gripper finger is wedge shaped and defines a plow type camming surface which as the carrier is caused to move toward the shed it engages the outer end of the cam member and lifts the latter so that the upper surface of the lip moves along the lower surface of said cam member as the carrier moves toward and into the shed. Actuation of the gripper finger during movement of the carrier toward the shed is thus prevented and substantially increases operating life of the gripper finger's biasing means.

It is a general object of the invention to increase the operating life of weft extending carriers for gripper type shuttleless looms.

A further object is to extend the life expectancy of gripper type wefi extending carriers by providing means to substantially reduce, relative to carriers of the prior art, the frequency of actuation of the carriers gripping finger during each picking cycle.

These and other objects of the invention will become more fully apparent by reference to the appended claims and as the following detailed description proceeds in reference to the figures of drawing wherein:

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view of a portion of a gripper type shuttleless loom showing the weft carrier control apparatus according to the invention applied thereto;

FIG. 2 is a plan view of the weft carrier in FIG. 1 showing the cam member for actuating the gripper finger to release the weft held thereby;

FIG. 3 is a view in end elevation of the apparatus in FIG. 1 as seen looking from the left-hand side thereof;

FIG. 4 is a view similar to FIG. 3 but showing the carrier withdrawn from the shed a distance sufficient for the cam member to actuate said carriers gripper finger;

finger and that position to which it is elevated to prevent actuation of said finger; and

FIG. 7 is a plan view of carrier in FIG. 6 showing the biasing means for laterally urging the cam member toward the carrier.

DESCRIPTION OF THE PREFERRED EMBODIMENT As the general construction and operation of a loom to which the present invention is applicable is well known and familiar to those conversant in the art, and as the invention is entirely concerned with an improved weft carn'er control apparatus for such looms, it is only considered necessary here to illustrate and describe those parts which are directly concerned with a preferred form of the invention.

In the figures of drawing the weft extending carrier is indicated generally by numeral 10 and is fixed to the end of a flexible tape 11 which in a known manner is caused to be wrapped about and extended from a tape wheel disposed at the side of the loom not shown.

The usual form of reed 12 is carried on a reciprocating lay beam 13 (FIG. 3) that is provided with a raceway 14 for guiding the flexible tape 11 and its carrier 10 during the performance of their intended function all of which is well known to those conversant in the weaving art.

The carrier 10 is of the conventional elongated configuration having upper and

lower surfaces

15 and 16 respectively that are disposed in spaced and aligned relation and which join at the leading end of the carrier to form a weft engaging hook 17. At the opposite or trailing end of the carrier the upper surface 15 tapers downwardly as shown at 18 in FIG. 6 where it joins with the lower surface 16 and forms a means for deflecting the warp yarns during withdrawal of the carrier from the shed. As shown in FIGS. 2 and 7 a web or rear wall 19 extends forwardly from the carriers trailing end for a portion of the length of the latter. In the space intermediate the upper and

lower surfaces

15 and 16 the carrier is provided with a gripper finger generally indicated by numeral 20 pivotably assembled intermediate at ends therein by means of a pin 21. This gripper finger 20 extends for substantially the full length of the space provided between the

surfaces

15 and 16 and is provided at its trailing end with an off-set lip generally identified by numeral 22 and disposed so as to protrude from the forward side of the carrier 10.

A biasing means in the form of a coil spring 23 (FIGS. 2 and 7) is located within the space provided between

surfaces

15 and 16 and is disposed so that one end thereof seats against the rear wall 19 and the other end against the inner or rearward side of the off-set lip 22. This coil spring 23 is assembled under tension and serves to continually urge the off-set lip forwardly which in turn urges the leading end 24 of the gripper finger (FIGS. 2 and 7) rearwardly and into a groove 25 of conforming configuration formed in the hook 17 where it is effective in gripping a pick of wefi 26 while drawing the same through the shed.

The forward vertical side of the off-set lip 22 has a portion of said side which is directed at an angle oblique to the remainder thereof and provides a first cam engaging surface 27 which serves to effect actuation of the gripper finger 20 and release of the weft as the carrier is being withdrawn from the shed. This offset lip 22 also includes at its leading end an extension of its upper horizontal surface which tapers angularly downward to meet the lower surface thereof and defines a second camming surface or a plow type cam 28. Cam 28 is effective on the weft carrier control apparatus, now to be described to prevent actuation of the gripper finger when the carrier is caused to move toward the shed.

The weft carrier control apparatus is identified generally in FIGS. 1, 3, 4 and 5 by numeral 29 and as shown in FIG. 3 includes a support bracket 30 which attaches to the lay beam 13 by means of cap screws 31. A locating bracket 32 is assembled to the support bracket 30 by means of bolts 33 and includes horizontally disposed

slots

34 and 35 through which said bolts 33 extend to provide means for controlling the distance between the shed and the control apparatus 29. The support bracket 30 also includes slots 36 and 37 that are vertically disposed through which bolts 33 extend and provides a means for vertical adjustment of the control apparatus 29 (FIG. 1).

A cam retaining member generally indicated by numeral 38 having a lower planar surface 39 assembles on the top of the locating bracket 32 by means of cap screws 40 and 41. These cap screws extend through slots 42 and 43 respectively in said planar surface and are tightened into aligned tapped holes provided in the locating bracket 32.

A cam member 44 is yieldably attached to the planar surface 39 by means of a pair of spaced and upwardly directed

bolt members

45 and 46 the heads of which are seated in appropriate apertures provided in the lower planar surface 39 (FIG. 4). Extending in an upwardly direction the shank portions of

bolts

45 and 46 pass through and beyond slots 47 (one only shown in FIG. 4) with their upper ends having a biasing means assembled thereon for continually urging cam member 44 to that position shown in FIGS. 1, 3 and 4. This biasing means includes coil springs 48 and 49 \(FIG. 1) which are assembled under tension on their

respective bolts

45 and 46 by means of

washers

50 and 51 and

nuts

52 and 53 respectively.

A further biasing means continually urges the cam member 44 in the direction of the indicating arrow 54 in FIG. 2 and includes a pair of spaced

spring wires

55 and 56 with one end of each being anchored in a centrally disposed and upwardly directed lug 57 which forms an integral part of the forward side of the planar surface 39. These

spring wires

55 and 56 are assembled in the lug 57 by means of set screws 58 (FIG. I) and extending from said lug the free ends of the spring wires are formed so as to bear against the forward side of the cam member 44.

Extending in the same general direction as

spring wires

55 and 56 and in close proximity with the latter lug 57 is provided with

fingers

59 and 60 having vertically disposed

recesses

61 and 62 respectively. These recesses are disposed in alignment with the ends of the spring wires and serve to provide clearance for the latter when cam member 44 is moved forwardly as will be more fully described hereinafter.

Referring now to FIGS. 1 and 2, which shows the carrier moving in the direction of the indicating

arrows

63 and 64 respectively, the cam engaging surface 27 of the off-set lip 22 is first caused to contact a tapered leading end 65 of the cam member 44 as the carrier is being withdrawn from the shed. Further movement of the carrier in this direction (FIG. 2) brings the off-set lip into contact with a rear camming surface 66 of the cam member and is effective in pivoting the gripper finger 20 and its leading end 24 a distance sutficient to cause the latter to release the weft 26. During this movement cam 44 is displaced slightly in a forward direction against the biasing force of

spring wires

55 and 56 so that the portions of said springs in contact with said cam are pushed into the clearance recesses 61 and 62 provided on

fingers

59 and 60.

To assure that the carrier and its tape 1 1 remain in their intended path of travel when the off-set lip 22 is in contact with the cam member 44 an elongated guide strip 67 is provided which is disposed so as to be engaged by the rear wall portion of the carrier. This guide strip has a cross-sectional configuration that is L- shaped and is attached to a generally T-shaped support bracket 68 by means of bolts 69 (one only shown in FIG. 3). Support bracket 68 overlies the pathway of the carrier and is adjustably assembled to a rearwardly directed shelf 70, by means of a bolt 71, that forms the upper surface of log 57.

Referring now to FIGS. 6 and 7 the trailing end of the cam member 44 is beveled on the lower portion thereof as shown at 72 and is disposed so as to be contacted by the plow type camming surface 28 when the carrier is caused to move toward the shed or in the direction of the indicating

arrows

73 and 74 in FIGS. 6 and 7 respectively. The plow type camming surface is effective as the carrier continues to move toward the shed in upwardly displacing the cam member 44 against the action of springs 48 and 49 (FIG. 4) and thereby prevent actuation of the gripper finger 20.

To summarize the operation the weft extending carrier enters a warp shed and is caused to meet the inserting carrier at a point near the center thereof where it receives and grips a length of weft adjacent to its cut end which was introduced by said inserting carrier. Both carriers then reverse their direction of travel and the extending carrier draws the weft through the retnainder of the shed. As the extending carrier is leaving the shed, the off-set lip 22 of its gripper finger 20 makes contact with cam member 44, and pivots said finger 6 and its leading end 24 a sufficient distance to release the weft and complete that particular pick.

When the carrier again moves toward the shed to repeat the cycle pivoting of the gripper finger 20 it is prevented by the plow type camming surface 28 of the off-set lip 22 raising and traveling along the underside of cam member 44.

Although the present invention has been described in connection with a preferred embodiment, it is to be understood that modifications and variations may be resorted to without departing from the spirit and scope of the invention as those skilled in the art will readily understand. Such modifications and variations are considered to be within the purview and scope of the invention and the appended claims.

I claim:

1. In a shuttleless loom of the type for inserting single picks of weft into separate sheds of warp threads by opposed reciprocating carrier members carried on the free ends of flexible tapes, an improved apparatus for controlling the actuation of the gripper finger of the weft extending carrier comprising:

a. camming means mounted on said loom in a manner providing for movement between an operative position where it is contacted by the weft carrier to releast wefi from the gripper finger and in inoperative position where no contact causing operation of the gripper finger is effected;

b. means defining an off set lip forming one end of the gripper finger disposed for operative engagement with said camming means having;

1. a forward vertical side defining a first cam engaging surface for actuating the gripper finger to release the weft as the carrier is being withdrawn from the shed;

2. an upper horizontal surface with a downwardly tapered leading end defining a second cam engaging surface for displacing said camming means to prevent actuation of the gripper finger during movement of the carrier into the shed, said camming means including:

A. a biasing means for returning said camming means to its operating position after being displaced by said second cam engaging surface; and

B. a further biasing means for continually urging said camming means toward its position of engagement with said first cam engaging surface.

Claims

1. In a shuttleless loom of the type for inserting single picks of weft into separate sheds of warp threads by opposed reciprocating carrier members carried on the free ends of flexible tapes, an improved apparatus for controlling the actuation of the gripper finger of the weft extending carrier comprising: a. camming means mounted on said loom in a manner providing for movement between an operative position where it is contacted by the weft carrier to releast weft from the gripper finger and in inoperative position where no contact causing operation of the gripper finger is effected; b. means defining an off set lip forming one end of the gripper finger disposed for operative engagement with said camming means having; 1. a forward vertical side defining a first cam engaging surface for actuating the gripper finger to release the weft as the carrier is being withdrawn from the shed; 2. an upper horizontal surface with a downwardly tapered leading end defining a second cam engaging surface for displacing said camming means to prevent actuation of the gripper finger during movement of the carrier into the shed, said camming means including: A. a biasing means for returning said camming means to its operating position after being displaced by said second cam engaging surface; and B. a further biasing means for continually urging said camming means toward its position of engagement with said first cam engaging surface.

2. an upper horizontal surface with a downwardly tapered leading end defining a second cam engaging surface for displacing said camming means to prevent actuation of the gripper finger during movement of the carrier into the shed, said camming means including: A. a biasing means for returning said camming means to its operating position after being displaced by said second cam engaging surface; and B. a further biasing means for continually urging said camming means toward its position of engagement with said first cam engaging surface.