US3096792A

US3096792A - Jacquard machines

Info

Publication number: US3096792A
Application number: US37898A
Authority: US
Inventors: Strach Lothar
Original assignee: Individual
Current assignee: Individual
Priority date: 1960-04-19
Filing date: 1960-06-22
Publication date: 1963-07-09
Anticipated expiration: 1980-07-09

Description

July 9, 1963 STRACH 3,096,792

JACQUARD MACHINES Filed June 22, 1960 2 Sheets-Sheet 2 LOT/MR STRHCH United States Patent 3,096,792 JACQUARD MACHINES Lothar Strach, Kohlhofweg 13, Wilhelmsfeld, Heidelberg, Germany Filed June 22, 1960, Ser. No. 37,898 9 Claims. (Cl. 139-59) In Jacquard machines the hooks are raised by means of grities which derive their motion from eccentrics, cams or cranks operatively connected to a main shaft usually disposed parallel with the axis of the card cylinder. Furthermore, it is usual to arrange for an additional shaft to be driven from the main shaft by chain and sprocket gearing or other drive transmitting means, the said additional shaft being adapted to drive the card cylinder or the perforated paper strip in step-by-step fashion by means of a star wheel or Geneva stop motion as well as providing the drive for actuating the needles in a Verdol, or endless paper type Jacquard.

In order to maintain the shed open for a period of time suflicient to enable the shuttle to pass through the shed from one side of the loom to the other side, when employing the eccentric, crank or like drive, the grifles must lift the hooks, and consequently the warp threads, a greater height than is necessary to provide suificient clearance for the shuttle. It will be appreciated that the shuttle commences its flight before the griifes have reached the top of their travel and it reaches the end of its flight after the griffes have started their downward movement. Consequently, the warp threads are subjected to greater tension than is needed to simply lift them a distance sufficient to clear the shuttle, the wider the loom and consequently the longer the flight of the shuttle, the greater the lift needed to permit the shuttle to complete its flight. Therefore the strain on the warp threads is substantially greater whenrweaving wide cloth than when weaving narrow cloth. This excessive tension or strain imparted to the Warp threads when the shed is opening, and then released when the shed closes, is one of the factors which cause the risk of warp breakage or damage.

The present invention is designed to provide means whereby excessive tension or strain of the warp threads during opening of the shed can be minimised, and s0 reduce the risk of warp breakage and permit a Jacquard loom to be operated at high speeds.

According .to the invention, toggle link or lever mechanism is interposed between the crank drive and a frame carrying the griifes. The .drive to the griifes is therefore transmitted through the toggle mechanism, and the latter can be so arranged as to provide a delay or dwell for the griifes in their upper positions whilst the shuttle passes through the shed.

One particular arrangement according to the invention of the drive for raising and lowering the grilfes will now be described by way of example only, with reference to the accompanying drawings in which,

FIGURE 1 is a diagrammatic side elevation of the driving mechanism,

FIGURE 2 is a diagrammatic view of the needle and card actuating means,

FIGURE 3 is a plan view of the drive shown in FIG- URE 2, and

FIGURE 4 is a detail view of an adjustable link incorporated in the mechanism.

Referring to the drawings, is the machine frame, 11 is the grifle frame, 12 is a griife, 13 is a hook and 14 is a needle which controls the hook 13. These parts are all of known construction. The griffe frame 11 is movable along a vertical guide 15 on the machine frame 10, and for this purpose it is connected by a link 16 to one end of a lever 17 the other end of which is pivotally mounted 3,696,792 Patented July 9, 1963 on the machine frame 10. A pair of

toggle links

18 and 19 are pivotally connected together at 20, the link 19 being pivotally mounted at 21 on the machine frame 19 and the link 18 having a pivoted connection 22 with the lever 17. The lever 17 is arranged to provide a mechanical advantage between the toggle mechanism and the griife frame. A connecting rod 23 is connected between the pivot 20 and a crank pin 24 on a flywheel 25 which is adapted to be driven in any convenient manner from the loom, not shown, on which the Jacquard machine is mounted. In the example shown the drive is by way of bevel gears 46 and a shaft 47.

It will be seen that with the mechanism so far described, as the wheel 25 rotates, the toggle links 18, 19, will be straightened and then returned to the angular position shown in the drawings, thus successively raising and lowering the lever 17 and the griffe frame 11. As the toggle links approach the straight line position (i.e. the position Where the stationary pivot 21, pivotal connection 20 and moving pivot 22 are in a straight line) the velocity ratio of the toggle joint increases towards infinity and there is a constantly reducing movement pivot 22 for successive increments of movements of the pivotal connection 20. The result of this is that for a considerable displacement of the pivotal connection 29 on either side of the straight line position, there is very little movement of the moving pivot 22, and consequently little movement of the griffes. In practice the toggle mechanism is arranged so that it only approaches and retracts from the straight line position at one side (i.e. it does not pass through the straight line position, although it may arrive at it, at the position of maximum lift of the griife).

The above explanation of the slowing down effect of the toggle mechanism assumes that there is constant linear velocity of the connecting rod 23. This is not the case in the arrangement described, because the connecting rod 23 is driven by the crank pin 24, and conse quently the linear velocity of the pivot 22 is constantly varying. The crank is disposed relatively to the toggle so that the crank pin passes through the position where the axis of rotation of the crank pin, the crank pin and the pivot 20 are all in a straight line, when the toggle is at the straight line position. As the crank pin is passing through this position there is very little movement of the pivot 20. When this effect is added to the slowing down effect of the toggle links, it will be appreciated that for a considerable angular rotation of the crank pin 24 (about 60 in practice) there is virtually no movement of the moving pivot 22 and consequently there is a substanti-al dwell period when the griffe is raised.

In order to bear the movement imparted to the lever 17 and the griife frame 11, the lever 17 has a longi tudinal slot 26 along which the pivot 22 is adjustable, a nut, not shown, being provided for locking the pivot 22 in any desired position along the length of the slot 26. It is preferred that the slot 26 follows an arc of a circle with its centre coincident with the axis of the pivot 21 when the toggle mechanism is in the position corresponding with the closed shed position of the warp threads. However, the slot 26 may be arranged on a straight path if desired. Another adjustment is provided for the connection between the connecting rod 23 and the pivot 20. For this purpose, the connecting rod 23 passes through the pivot 20 and it is screw threaded,

nuts

27 and 28 being engaged with screw threads on opposite sides of the pivot 20 so that by adjusting the

nuts

27 and 28 the effective length of the connecting rod can be varied.

A still further adjustment is provided for the toggle link 18 in that the said link is made in two relatively adjustable parts whereby the length of the link can be varied, and means are provided for locking the said two aooavez relatively adjustable parts to one another after adjustment. This toggle link 18 is illustrated in FIGURE 4 where it will be seen that the two parts of the link 18 are indicated at 18' and 18 respectively, each part hav-' ing a series of serrations 44 adapted to interengage with one another, the part 18' having a slot 45 and the part 13 having two holes 56, a bolt 57 being passed through each of the holes 56 and through the slot for securing the two parts 18' and 18" together. To adjust the link 18, the bolts 47 are loosened sufliciently to permit disengagement of the serrations 44, whereupon the parts 18" and 18 can be displaced relatively to one another either to lengthen or shorten the link 18 as desired, and by finally re-tightening the bolts 57 the serrations 44 will be re-engaged so as to rigidly secure the two parts 18' and 18" together.

It will be noted that three adjustments are provided, that is, the slot 26 in the lever 17, the connection between the connecting rod 23 and the pivot 20; and the telescopic toggle link 18, the first two adjustments being arranged so as to permit infinite adjustments between predetermined limits. The adjustable toggle link is adjustable in very short steps corresponding with the pitch of the teeth of the serrations 44, but as the link 18 would normally not be adjusted independently of one or both of the other two adjustments, the final adjustment for; the movements imparted to the griffe frame can be regarded as infinately variable without definite steps. These three adjustments enable the height of the lift of the griffes to be varied, and the duration of lift to be determined accurately in accordance with the shuttle flight and the width of the cloth being woven, so as to minimise the extent and duration of stretch imparted to the warp threads in formation of the shed.

The Jacquard machine illustrated is a Verdol or endless paper type Jacquard and consequently it has a feed cover 30, which is the equivalent of the cylinder of a normal Jacquard, and over which the perforated paper strip or card 31 passes for co-operation with vertical feeler wires, one of which is shown at 32. Each feeler wire 32 has a loop 33 through which an auxiliary needle 34 passes, the auxiliary needle 34 having a head 35 for engagement with the end of the corresponding needle 14. This mechanism operates in the normal manner, the stepby-step feeds for the paper card is provided by a pig wheel 59 and star wheel 36 forming a stop Geneva motion, the grid 38 actuates the auxiliary needles and is reciprocated in the normal manner by means of a cam 39 co-operating with a lever 40 pivoted at 41 on the machine frame and connected by a link 42 to the grid 38. The peg wheel '59 is mounted directly on the shaft '43 on which the wheel 25 is mounted. It will be seen therefore, that additional shafts are not required as all mechanisms are driven from one main shaft.

As a Jacquard is essentially a reciprocating or jerking mechanism, it is desirable to design the mechanism in such a way as to minimise the risk of fracture of the main needles 14. This can be effected by arranging for the needles 14 to be as short as possible, and for this reason the main shaft 43 has been disposed clear of the space occupied by the hooks. It is usual in Jacquard machines for the main shaft to extend through a gap left at the centre of the bank of hooks, and consequently the needles must be longer than would be necessary if the said gap was not present. As shown in the drawings, the main shaft is disposed beneath the auxiliary needles 34, and thus being entirely clear of the bank of hooks, no gap is required in the bank of hooks and the needles aretherefore made as short as possible. This arrangement of the main shaft 4-3 also enables the overall dimensions of the machine to be kept as small as possible, resulting in increased stability and eifecting a considerable saving of material, particularly in the machine frame.

The conventional Verdol Jacquard machine in conneclion With Which the present invention is illustrated is disclosed in the following publications, to which reference is made for any required detail of structure and/or operation.

Mechanism of Weaving by Thomas W. Fox, published by McMillan and Co. Ltd., London, England in 1911, see FIGURE 96 on page 178.

Jute and Linen Weaving by Woodehouse and Milne, published by McMillan and Co. Ltd., London, England 1914, see page 259.

British Patent No. 1,751/ 1884.

An advantage of the toggle link mechanism for transmitting the drive to the griffes is that as the warp tension increases during opening of the shed, the rate of shed opening progressively decreases and at the maximum shed opening when the warp tension is greatest, the shed opening movement approaches zero and the mechanical advantage provided by the toggle links approaches infinity. Consequently at the point of maximum load the driving power required is at a minimum, and the reaction forces are absorbed by the machine frame through the shortest path by way of the toggle levers.

What is claimed is:

1. Jacquard mechanism for a textile Weaving loom comprising a griffe, means mounting said grille for limited rising and falling movement; a first toggle link connected between a stationary pivot and a pivotal connection with a second toggle link, said second toggle link being connected between said pivotal connection and :a moving pivot forming part of a mechanism for raising and lowering said grifle, rotating drive means; a crank pin carried by said drive means, and rotatable with said drive means about a crank axis, and a connecting rod connected between said crank pin and said pivotal connection for transmitting drive from said crank pin to said toggle links; said drive means, connecting rod and toggle links being so relatively disposed that said crank pin passes through the position where said crank axis, said crank pin and said pivotal connection are in a straight line at approximately the position of maximum lift of said griffe.

2. Jacquard mechanism for a textile weaving loom comprising a grille; means mounting said grifie for limited rising and falling movement; a first toggle link connected between a stationary pivot and a pivotal connection with a second toggle link, said second toggle link being connected between said pivotal connection and a moving pivot forming part of a mechanism for raising and lowering said griife; rotating drive means; a crank pin carried by said drive means and rotatable with said drive means about a crank axis; and a connecting rod connected between said' crank pin and said pivotal connection for transmitting drive from said crank pin to said toggle links; said drive means connecting rod and toggle links being so relatively disposed that said crank pin passes through the position where said crank axis, said crank pin and .said'pivotal connection are in a straight line at approximately the position of maximum lift of said griife; said toggle links being further arranged so that said stationary pivot, said pivotal connection and said moving pivot are in approximately a straight line at the position of maximum lift of said griife.

3. Jacquard mechanism according to claim 2, wherein said mechanism for raising and lowering said griffe includes lever means for obtaining mechanical advantage between said moving pivot and said g'riife.

4. Jacquard mechanism according to claim 3, wherein said moving pivot is carried by said lever means and said moving pivot is adjustable on said lever means to vary the velocity ratio.

5. Jacquard mechanism according to claim 2, comprising a pattern feeding shaft, a star wheel fixed on said pattern feeding shaft, a driving shaft for said drive means adjacent said pattern feeding shaft, a peg wheel cooperating with said star wheel to produce step-by-step rotation of said pattern feeding shaft, and means mounting said peg wheel directly on said driving shaft.

6. In a Jacquard mechanism for a textile weaving loom, a support, a griife mounted on said support for controlled up and down movement, and means for controlling said movement comprising a lever pivoted upon said support and operably connected to said griffe, toggle linkage pivotally connected between the support and said lever, and variable drive means operably connected to said toggle linkage for cyclically actuating said griffe while providing a dwell period of predetermined length when the griffe is in raised position.

7. In the mechanism defined in claim 6, means for adjusting said drive means and said toggle linkage for varying the movement of said grille.

8. Jacquard mechanism according to claim 2, in which said connecting rod is adjustable to vary its efiective length.

9. Jacquard mechanism according to claim 2, in which at least one of the toggle links is adjustable to vary its efiective length.

References Cited in the file of this patent UNITED STATES PATENTS 497,277 Hardwick May 9, 1893 498,912 Evans June 6, 1893 622,257 Pavia Apr. 4, 1899 FOREIGN PATENTS 355,236 France Aug. 22, 1905 1,223,696 France Feb. 1, 1960

Claims

1. JACQUARD MECHANISM FOR A TEXTILE WEAVING LOOM COMPRISING A GRIFFE, MEANS MOUNTING SAID GRIFFE FOR LIMITED RISING AND FALLING MOVEMENT; A FIRST TOGGLE LINK CONNECTED BETWEEN A STATIONARY PIVOT AND A PIVOTAL CONNECTION WITH A SECOND TOGGLE LINK, SAID SECOND TOGGLE LINK BEING CONNECTED BETWEEN SAID PIVOTAL CONNECTION AND A MOVING PIVOT FORMING PART OF A MECHANISM FOR RAISING AND LOWERING SAID GRIFFE, ROTATING DRIVE MEANS; A CRANK PIN CARRIED BY SAID DRIVE MEANS, AND ROTATABLE WITH SAID DRIVE MEANS ABOUT A CRANK AXIS, AND A CONNECTING ROD CONNECTED BETWEEN SAID CRANK PIN AND SAID PIVOTAL CONNECTION FOR TRANSMITTING DRIVE FROM SAID CRANK PIN TO SAID TOGGLE LINKS; SAID DRIVE MEANS, CONNECTING ROD AND TOGGLE LINKS BEING SO RELATIVELY DISPOSED THAT SAID CRANK PIN PASSES THROUGH THE POSITION WHERE SAID CRANK AXIS, SAID CRANK PIN AND SAID PIVOTAL CONNECTION ARE IN A STRAIGHT LINE AT APPROXIMATELY THE POSITION OF MAXIMUM LIFT OF SAID GRIFFE.