US3833027A

US3833027A - Double lift dobby

Info

Publication number: US3833027A
Application number: US00319308A
Authority: US
Inventors: Z Pavlica
Original assignee: Elitex Zavody Textilniho
Current assignee: Elitex Zavody Textilniho
Priority date: 1972-01-04
Filing date: 1972-12-29
Publication date: 1974-09-03
Anticipated expiration: 1991-09-03
Also published as: CS158809B1; CH549667A; ES410335A1; FR2167693A1; JPS4877157A; GB1392729A; IT972974B; DE2300032A1; FR2167693B1

Abstract

A double lift dobby for dobby looms, jacquard looms and the like comprising a first and second double arm crank, each of which is rotatably journaled about independent axes spaced from and parallel to each other. One arm of each of the cranks is provided with latch means for selectively engaging a corresponding one of a driven pair of lifting knives. The cranks are thereby rotatable about their axes by and conjointly with the lifting knife after such engagement. The other arms of each of the cranks is interconnected with the means for raising and lowering the heald frame which comprises a lever connected at one end to the first of the cranks and at the other end to the means for lowering the heald frame and a tie rod connected at one end of the second of the cranks and at its other end between the ends of the lever.

Description

Pavlica 4] DOUBLE LIFT DOBBY [75] Inventor: Zdenek Pavlica, Jicin,

Czechoslovakia [73] Assignee: ELITEX Zavody textilniho strojirenstvi, generalni reditelstvi, Liberec, Czechoslovakia [22] Filed: Dec. 29, 1972 [21] Appl. No.: 319,308

[30] Foreign Application Priority Data Jan. 4, 1972 Czechoslovakia 3672-72 [52] US. Cl. 139/71 [51] Int. Cl. 0031': 1/06 [58] Field of Search 139/66 R, 66 A, 68, 71, 139/74, 331

[56] References Cited UNITED STATES PATENTS 3,703,195 11 1972 Schwarz m 139/71 FOREIGN PATENTS OR APPLICATIONS 959,899 3/1957 Germany 139/71 145] Sept. 3, 19 74 853,856 11/1960 Great Britain 139/71 657,412 9/1951 Great Britain 1,106,704

Primary Examiner-James Kee, Chi

Attorney, Agent, or Firm-Murray Schaffer [57] ABSTRACT v g A double lift dobby for dobby looms, jacquard looms and the like comprising a'first and second double arm crank, each of which is rotatably journaled about independent axes spaced from and parallel to each other. One arm of each of the cranks is provided with latch means for selectively engaging a corresponding one of a driven pair of lifting knives. The cranks are thereby rotatable about their axes by and conjointly with the lifting knife after such engagement. The other arms of each of the cranks is interconnected with the means for raising and lowering the heald' frame which comprises a lever connected at one end to the first of the cranks and at the other end to the means for lowering the heald frame and a tierod connected atone end of the second ofthe cranks and at its other'end between the ends of the lever. 1 I

3 Claims, 1 Drawing Figure 5/1961 Germany 139/71 DOUBLE LIFI DOBBY BACKGROUND OF THE INVENTION The present invention relates to a double lift dobby loom, jacquard loom and the like and particularly to an arrangement for linking double lift mechanism of the dobby to an associated heald frame.

In conventional looms the shedding operation is performed by the cooperative manipulation of the several harness heald frames and the associated hook cords. Conventionally this is accomplished by an arcuately moving lifting knife adapted to engage the hook cords and by a link connected to the heald frame which includes crank means selectively engageable with the lifting knife to transmit the motion of the driven lifting knives to the heald frame. In double lift dobby looms and similar jacquard looms a pair of lifting knives are arranged in associationwith each other and require a pair of corresponding lifting cranks which are interconnected with the means for raising and lowering the heald frame. The interconnection between the two crank levers has generally employed a balancing or levelling lever by which the motion of either or both of the lifting cranks is transmitted to the heald frame. Such interconnections have had the disadvantage in that the motion of the balancing lever is derived from its center which has half or less of the lift of the lifting cranks. Thus the extent of movement of the balance lever is small and must be-multiplied several times in order to sufficiently actuate the heald frame.-

It is the object of the present invention to provide an arrangement which overcomes the disadvantages of the prior art and provides a dobby which maintains its ability of double lifting but which does not require a complex mechanism for multiplying and transmitting the motion of the lifting cranks to the heald frame.

In particular, the present invention is directed to an improvement for the form of a dobby mechanism described in our copending application filed on even date herewith corresponding to Czechoslovak patent appli cation No. PV 33-72, dated Jan. 4, 1972, to which reference is made here as if more fully set forth.

These objects, other objects and numerous advantages will be seen from the following disclosure of the preferred embodiments of the present invention.

SUMMARY OF INVENTION According to the present invention a double lift dobby for dobby looms, jacquard looms and the like is provided, comprising a first and second double arm crank each of which is rotatably journaled about independent axes spaced from and parallel to each other. One arm of each-of the cranks is provided with latch means for selectively engaging a corresponding one of a driven pair of lifting knives. The cranks are thereby rotatable about their axes by and conjointly with the lifting knife after such engagement. The other arm of each of the cranks is interconnected with the means for raising and lowering the heald frame which comprises a lever connected at one end 'to the first of the cranks and at the other end to the means for lowering the heald frame and a tie rod connected at one end of the second of the cranks and at its other end between the ends of the lever. According to this structurean articulated linkage is provided wherein the means for raising and lowering the heald frame is actuable upon rotation of the distance between the point of connection of the tie rod tothe lever and the point of connection of the lever withthe means for raising and lowering the heald frame to the entire length between the connecting ends of the lever itself. This ratio thus insures the proper transmission of the movement of thecranks. I

Still further, in accordance with the present invention, the tie rod is provided so that it may be adjustably positioned at each of its ends to the second crank and-- /or to the lever respectively.

Full details of the present invention are given in the following description of the preferred embodiment and will be seen in the attached drawing-thereof.

BRIEF DESCRIP'HONOF THE DRAWING I In the drawing:

The FIGURE is a side view of that portion of a high speed dobby mechanism employing-the present invention.

DESCRIPTION OF THE INVENTION The following description and the attached drawing provide the structure and operation of a single double lift unit, similar to the type described'in the aforementioned copending application, to which reference might ber of healds in the harness. Consequently, while only one such unit is shown here, it will be appreciated that a conventional loom will. contain several of them, mutually identical. 7

As seen in the figure, the dobby mechanism comprises a pair of fixed axle shafts la and lb on which are rotatably joumaled double arm crank levers 2 and 3 respectively carrying at their upper ends pivot pins 4a or 4b about which a latching rocker 5a or 5b is secured.

The shaft axles la and lb each journal, in addition, a carriertnot seen) on the outer end of whichthere is respectively mounted a lifting knife 6a or 6b. Each of the carriers is provided with means such'as that shown in the aforementioned copending application by which the lifting knives may be given a reciprocatory or oscillatory swinging motion in an arcuate path about a center, which is identical with the center of the shaft axles la and 1b. This center is also identical with the center of arcuate movement of the latches 5a and 5b, as will be obvious from the construction. The rocker latches mounted are provided with their own stop means which are adapted to engage and abut a portion of the lifting knife, the lifting knife itself being arranged at a height permitting the inner hook at the end of the latching rocker to be able to be locked over and securely engage the lifting knife for conjoint movement.

When it isdesired to either effect movement of the crank 2 or the crank 3 or to possibly move both simultaneously, the lifting hook mounted at the end of its upper arm is depressed to be shifted downwardly by an impulse directed in the direction of the arrow C or D, so that its outer end is removed from the catches 8a or 8b and its inner end is firmly locked in engagement with the appurtenant lifting knife 60 or 6b. Preferably, the shifting of the rocker latch occurs during the rest dwell of the dobby mechanism as a whole, that is, when the lifting knife abuts against the stop on the upper amt of the crank and when the upper arm of the crank itself abuts against the

fixed stops

9a or 9b. The locking of the latching rocker on to the lifting knife thereafter permits the lifting knife 6a or 6b, which is positively driven to oscillate about the center of the axles 1a and 1b, to conjointly carry with it and move in a coincident arcuate path the lifting cranks 2 or 3; turning the lifting crank 3 counter clockwise while turning the lifting crank 2 clockwise. in the reverse motion created by the dobby drive the lifting knives 6a or 612 carry the levers 2 and 3 in the contrary direction swining them outwardly from each other and placing them back to their initial position against the

fixed stops

9a and 9b. When this occurs the springs 7a and 7b again act to lock the latches over the stationary catches 8a and 8b maintaining the lifting cranks 2 or 3 at rest, where they remain so so long as an impulse is not exerted in either of the directions C or D.

Each of the lifting cranks is provided with a depending arm extending at an angle away from the arm on which the latches are mounted. The end of the depending arm of the lifting crank 2 is pivotally connected at a point 10 to the end of a tie rod 11 which is pivotally connected at its opposite end 12 to a balancing lever 13. The balancing lever 13 is pivotally connected at one end 14 to the end of the depending arm of the lifting crank 3 and its opposite end 15 at a pivotal connection with a bar or shaft 16 secured by a means arrangement to the heald frame.

it will be seen that when the lifting crank 2 is rotated clockwise by its engagement with its associated lifting knife, the point 10 swings from its initial position E through an are 01 into a lifting position F while if the lifting crank 3 is swung counter-clockwise from its initial position G through an angle a into its lifting position H and the balancing lever 13 will move correspondingly and consequently actuate the connection 16 with the heald frame.

Upon operation of the dobby to move either or both of the lifting cranks the balancing lever might take one of three variations:

I. If the liftingcrank 2 is maintained at rest and the lifting crank 3 is moved counter-clockwise then the end 14 of the lifting crank 3 will swing through an are 1,, from its initial position G into the position H and back, and the balancing lever 13 will pivot about the point 12 at which it is connected to the tie rod 11, since this point 12 remains at its initial position because the tie rod 11 is tied at poing 10 to the lifting crank 2 which is held stationary in its rest position. Thus point 15 at the end of the lever 13 derives a positive swinging motion moving in arc 1 from position] into position K and back.

2. if the lifting crank 3 is maintained at its rest position and the lifting crank 2 is made to. perform its swinging motion then the point 10 at the end of the lifting crank 2 swings an arcuate distance I, from position E into position F and back. The tie rod 11 is thus caused to pivot the lever 13 about the point 14 at the end of the depending arm of the lifting crank 3, moving the lower end 15 of the lever from its position J into the position K as in the first variation.

3. Should both the lifting cranks 2 and 3 be caused to sequentially swing then a double lift effect can be made to occur in that the end of the lever 13 can be made to remain for the required number of lifts in the position K and consequently the heald frame can be made to remain stationary for a period of time in its upper position. This double lift effect can be initiated when either one of the lifting cranks 2 and 3 are swung clockwise or counter-clockwise in to their lifting position and then sequentially placing the other lifting crank into its lifting position. By alternating actuation on the latches of the rockers 5a and 5b during the oscillating or reverse motion of the dobby, in sequence, then the end of the balancing lever 13 can be maintained in position K. In this manner the point 14 at the end of the depending arm of the lifting crank 3 moves from position H to the position G and the point 10 at the end of the depending arm of the lifting crank 2 movesfrom the position E into position F so that the pin 15 remains at the point K indefinitely.

The length of the shift of the point 15 between the positions J and Kcan be adjusted by varying the length of the tie rod 11 or its point of connection 12 on the lever 13. This can easily accomplished by providing the tie rod 11 and the lever 13 with several-receiving holes at each end through which the

pins

10 and 12 securing the tie rod to the crank 2 and lever 13 and can be easily inserted. The relationship of the dimensions of the crank arms with respect to the tie rod and lever 13 are of importance with providing the proper swing unto the lever 13 and thus the proper length of actuation of the member 16 so as to lift the heald a predetermined distance. To understand this relationship the following notations have been used in the drawings.

. d: represents the overall length of the balancing lever 13, a: represents the length of the depending arm of the lifting crank 2,

b: represents the length of the depending arm of the lifting crank 3,

the angle alpha 6! represents the angular deviation of the separate arrns aand b of each of the swinging levers of each of the lifting cranks ,2 and 3.

1 represents the lifting length or swing arc of the point 10 at the end of the depending arm of the lifting crank 2, I equals the lifting length or swing arc of the point 14 at the end of the'depending arm of the lifting crank 3, and

I equals the length of the resulting lift or swing arc point 12 and the end 15 of the lever .13. As has been explained further, it may be desirable to adjust or vary the position of the point 12 with regard to the ends of the lever 13 so that the fulcrum point which it establishes when the lifting crank 2 is held in rest or dwell position can be varied and length of the arm between point 12 and point may consequently be varied.

d: The optimum movement of the lever 13, when engaged in the first variation noted above, is accomplished when the point 15 is swung in an are having the relationship l =1 (c/d c) The optimum arrangement for proceeding under the second variation is accomplished when the relationship exists for the swing arc of point 15.

From the above relationships it follows that since 1 as in the first case, is equal to 1 in the second case that the actual relationship of the arms a and b can be expressed as follows:

Thus the preferred ratio stated earlier is'satisfied.

By either shortening the connecting rod 11, or by shifting the position of point 10 on the depending am of the lifting crank 2 or the point 12 on the lever 13, the distance between the lever 13 and the crank 2 is varied and thelength of the arm C is varied and thus the swing of the lever 13 from position J to K can be varied. In this way the possibility is established for changing the movement of the arm 13 to vary the amount of lift or the distance that the heald frame is caused to be raised and lowered. Y Y

It will be seen from the foregoing that the articulated connection created by the lever 13 and the tie rod 11 create a lever system having two fulcrum points. With the fulcrum at point 12, when the lifting crank 2 is held stationary, the lever 13 acts as a first order lever. On the other hand with the lifting crank 3 held stationary or in the rest position and the point 14 constituting the fulcrum, the lever l3 acts as a second order lever. From ther or both the levers can be transmitted directly to the apparatus for raising or lowering the heald without any subsequent multiplication. By selecting the proper dimensions the crank arms and levers as well as the connecting rod the exact can be obtained.

Various modifications and changes will suggest them selves to those skilled in this art. Accordingly, the present disclosure is intended to be illustrative only and not limiting the scope of the invention in any manner.

What is claimed is: 1 l. A double lift dobby, jacquard loom and the like having a first and a second double arm crank, each crank being rotatably journaled about an axis spaced from and parallel to each other, one arm of each of said cranks being provided with means for selectively engaging one of a pair of driven lifting knives to be rotated thereby about its axis, the other arm of each of said cranks being articulatingly interconnected with the means for raising and lowering the heald frame, said interconnection comprising a lever connected at one end to the first of said cranks and at its other end to the means for raising and lowering the heald frame and a tie rod connected at one end to the second of said cranks and at its other end to the lever between the ends thereof to provide an articulated linkage having a pair of spaced fulcrum points so that one of .said fulcrums-is employed on the actuation of a selected one of said cranks and'wherein said means for raising. and lowering the heald frame is actuable on rotation of one or both of said cranks. V

2. The dobby according to. claim 1 wherein the size of the other arm of said second crank relative to the other arm of said first'crank is equal to the ratio of the this arrangement it will be obvious that the numerousadvantages can be obtained by which the motion of eidistance between the connection of said tie rod to said lever and the connection of said lever to said means for raising and lowering the heald frame to the entire length between the connecting ends of said lever.

3. The dobby according to claim 1 wherein the tie rod is adjustably positioned at each end to said second crank and said lever respectively.

Claims

1. A double lift dobby, jacquard loom and the like having a first and a second double arm crank, each crank being rotatably journaled about an axis spaced from and parallel to each other, one arm of each of said cranks being provided with means for selectively engaging one of a pair of driven lifting knives to be rotated thereby about its axis, the other arm of each of said cranks being articulatingly interconnected with the means for raising and lowering the heald frame, said interconnection comprising a lever connected at one end to the first of said cranks and at its other end to the means for raising and lowering the heald frame and a tie rod connected at one end to the second of said cranks and at its other end to the lever between the ends thereof to provide an articulated linkage having a pair of spaced fulcrum points so that one of said fulcrums is employed on the actuation of a selected one of said cranks and wherein said means for raising and lowering the heald frame is actuable on rotation of one or both of said cranks.

2. The dobby according to claim 1 wherein the size of the other arm of said second crank relative to the other arm of said first crank is equal to the ratio of the distance between the connection of said tie rod to said lever and the connection of said lever to said means for raising and lowering the heald frame to the entire length between the connecting ends of said lever.