US3290730A

US3290730A - Needle bar mechanism for drawing fibers

Info

Publication number: US3290730A
Application number: US380476A
Authority: US
Inventors: Herubel Jean Frederic
Original assignee: N Schlumberger SAS
Current assignee: N Schlumberger SAS
Priority date: 1963-07-05
Filing date: 1964-07-06
Publication date: 1966-12-13
Anticipated expiration: 1983-12-13
Also published as: GB1049700A; FR1376547A; BE649884A; CH416400A; DE1510421B1

Description

Dec. 13, 1966 J. F. HERUBEL NEEDLE BAR MECHANISM FOR DRAWING FIBERS Filed July 6, 1964 5 Sheets-Sheet 1 J. F. HERUBEL NEEDLE BAR' MECHANISM FOR DRAWING FIBERS Dec. 13, 1966 Filed July 6, 1964 5 Sheets-Sheet 2 Dec. 13, 1966 J. F. HERUBEL. 3,290,730

NEEDLE BA R MECHANISM FOR DRAWING FIBERS Filed July 6, 1964 5 Sheets-Sheet 3 3,290,730 NEEDLE BAR MECHANISM FOR DRAWING FIBERS 4 Claims. ((31. 19-129 The invention relates to a transfer device for needle bar mechanisms of the gills, intersecting or other type, employed in drawing fibres such as wool, flax, chopped synthetic or other fibres.

In mechanisms of this nature, a translatory motion is imparted to the bars by means of screws having a deepcut thread in which the extremities of the bars engage. When the latter have reached the end of their useful stroke, they are transferred to return screws extending parallel to the so-c-alled work screws, but at a different height. At the end of their return stroke, the bars are again transferred into engagement in the work screws.

Diflicult problems arise in transferring the bars from the return screws to the work screws in particular. This transfer should be performed quickly, and during the transfer the bars should be guided in accurate manner to ensure their correct engagement in the threads of the screws. The bars should however be braked towards the end of this transfer motion at least, to prevent their stopping at the 'end of the transfer motion and engendering violent shocks apt to cause damage to the mechanism and to the bars themselves.

It has already been suggested that the bars be guided during their transfer from the return screws to the work screws, and inversely, by means of guide elements possessing a certain degree of elasticity, or resiliently mounted guide elements, in such manner as to exert an elastic thrust on the bars and thereby provide a braking action. A device of this kind cannot however be contrived in such manner as to assure correct guiding and braking at the same time, one of these functions being performed at the expense of the other in all cases.

Effective braking moreover involves the application of a substantial elastic force in these devices which causes considerable wear.

It has also been suggested to incorporate resilient abutments against which the bars come into contact at the end of their transfer motion, but devices of this kind can cause risky rebounds.

The present invention has as its object a transfer device of the kind referred to, which is essentially characterized by an assembly comprising separate guiding devices and braking devices, each of these devices. having an active surface co-operating with the extremities of the bars about to be transferred in motion relative to the said surfaces, which latter are formed in such manner that the first essentially provides guiding and the second the braking action for the said bars, the assembly being devised in such manner that the two aforesaid active surfaces cooperate simultaneously with the same bar, at least along a portion of the transfer stroke of the same.

According to another feature of the invention, the elements of the guide devices and the elements of the braking devices having the corresponding active surfaces, are

' United States Patent Patented Dec. 13, 1966 displaceable independently of each other and are acted upon by separate or different forces, preferably of elastic nature.

According to another feature of the invention, the active surfaces of the guide devices and of the braking devices are separately carried each by a pivotally mounted lever, these two levers preferably being bearing-mounted on the same spindle.

According to another feature of the invention, the active surface of the guide element is substantially flat, whereas the active surface of the braking device comprises an incurving portion assuring progressive braking, at least towards its run-off extremity, this incurving portion preferably following a flat portion.

According to another feature of the invention, the active surfaces or portions of active surfaces which are fiat, of the braking devices and guiding devices, have a relatively small width, the width of the incurving portion of the active surfaces of the braking devices being substantially greater than the width of the aforesaid fiat portions.

The invention is particularly described hereinafter by way of example and not of limitation, with reference to the accompanying drawings, in which:

FIGURES 1 and 2 show a transfer device according to the invention in two different operating positions, in schematic elevation, and

FIGURE 3 is an end view of the device of FIGURES 1 and 2.

In the drawings, 1 represents a return screw and 2 a work screw, correspondingly intended to co-operate with one extremity of the bars. These screws have corresponding deep-cut threads 1a and 2a intended to impart a translatory motion according to the corresponding arrows F and F to needle bars 3 whose extremities are engaged in these threads (see FIGURE 3).

Along their return path according to the arrow F and along their working stroke according to the arrow F the bars 3 are guided by guideways or tracks 4 on the return path, and guideways or

tracks

5 and 6 on the work path.

When a bar reaches the end of its return stroke as shown for the bar 3a in FIGURE 1, it must be transferred to the work screw 2. A rotary cam is incorporated for this purpose, comprising two

opposed projections

8 and 9 which act on a bar situated in the position 3a in such manner as to lift the same from the lower to the upper position, as far as the screw 2. In FIG. 2, 3b indicates an intermediate position of the bar lifted by the projection 8. During a part of this transfer motion, the bar is guided at one side by means of the extremity 10 of the guide track 5, which extremity is appropriately formed to engage in a groove of corresponding shape marked 11 which is formed in the corresponding face of the bar.

At the opposite side with respect to the extremity 10, the bar about to be transferred is guided by means of a guide lever 12 comprising a flat guide surface 12a cooperating with the corresponding flat surface'of the bar as shown by way of example for the bars 3a and 3b. The lever 12 is solid with a hub 13 with which it is bearing-mounted on a spindle 14.

According to the invention, the lever 12 with its surface 12a essentially performs the guiding -action for the bar which is to be transferred, whereas the braking action on the bar is asured by another pivotally mounted lever 16 whose hub 15 is equally bearing-mounted on the spindle 14.

The active surface of the lever 16 comprises a flat portion 16a, an incurving portion 16b, and a further flat portion 160.

The

levers

12 and 16 are acted upon by the

corresponding return springs

17 and 18.

The device according to the invention operates in the following manner:

When a bar reaches the position 3a at the end of its return stroke, it comes into contact with the flat active surface 12a of the guide lever 12.

The rotary motion of the screw 1 imparts a motion to the bar situated in the position 3a in the sense of the arrow F causing the lever 12 to pivot slightly against its spring 17 and bringing the bar into the position in which the extremity of the guide track can engage in the groove 11 of the bar. The projection 8 of the rotary cam 7 moreover engages beneath the bar in such manner as to lift the same.

At the beginning of the transfer of the bar 3a (FIG- URE 1) from the screw 1 to the screw 2, the said bar 7 improved manner.

is in contact only with the active surface 12a of the pivot lever 12, since the pivot lever 16 is thrust back against its return spring 18, due to the fact that its surface 160 is in contact with the bar 30 which has previously been transferred.

In a following stage (not illustrated) of the transfer of the bar 3a, the latter is raised by the projection 8 of the cam 7. At the same time, the pivot lever 16 is released by the displacement of the bar 3c in the sense of the arrow F in such manner that its flat surface 16a also comes into contact with the bar which is being transferred.

FIGURE 2 shows a bar 3b towards the end of its transfer motion. At the instant shown, the bar is satisfactorily guided, on the one side by the guide extremity 10 engaged in its groove 11, and on the other by the flat guide surface 12a of the pivot lever 12 which is applied against the bar by its spring 17.

The upper outer edge of the bar 3b has moreover come into contact with the incurving surface 16b of the braking lever 16, in such manner as to cause the latter to pivot against its spring 18. The lever 16 is thrust backwards progressively as the bar 3b rises, owing to the curvature of the surface 16b which assures progressive braking of the bar 3b.

It should be noted that during this braking action performed by the lever 16, the bar 3b still remains guided between the guide extremity 10 and the flat guide surface 12a of the lever 12.

It is notable moreover that the friction of the bars against the flat surface 12a of the lever 12 is relatively low owing to the small force required for guiding purposes. The braking action on the incurving part 16b of the surface of the lever 16 is very effective, despite the quasi-linear contact between the bar and this surface, due to the relatively great width of the latter.

At the end of its transfer motion, the bar 3c released from the guide extremity 10 is placed on the guide track 5 by the guide surface 12a of the lever 12, due to the pivoting motion of the latter by the spring 17. The extremity 160 of the lever 16 then correctly engages the bar 3c in the thread 2a of the screw 2.

The guiding and braking actions are performed by separate elements according to the invention, so that the forms of these elements and the return forces applied thereto may be adapted precisely to their corresponding tasks.

The braking action exerted at the end of the stroke of the bar occurs in progressive manner and along an appreciable part of this stroke.

The flat operating surface of the guides is of adequate size to reduce wear to a minimum. The incurving braking surface is of relatively great width to insure optimum efiiciency and to reduce wear to acceptable values.

Since the transfer of the bars is controlled in reliable manner along the full length of the transfer stroke, cor rect engagement in the screws is assured.

Due to very effective locking of the bar in position after engagement in the screw, any danger of jamming in the screw threads because of rebound off of the upper guide track, is eliminated.

If one of the elements were to break, for example a pivot lever or a return spring, the unbroken elements are able to perform on a temporary and at least partial basis, both the guiding and braking actions, in order to prevent serious and costly damage.

The from of embodiment described hereinabove and illustrated in the accompanying drawings is given by way of example only, and it is plain that the form, nature, disposition and mounting of the elements may be modified in any appropriate manner without thereby exceeding the scope of the invention. The return springs of the pivot levers may thus be replaced by other return devices. These return devices are preferably adjustable and/ or interchangeable moreover, as are the pivot levers as such. Although the application of the invention has been illustrated only in respect of transfer from the return screws to the work screws, the invention is evidently applicable in analogous manner to the transfer of the bars from the work screws to the return screws. In this respect a device similar to that already described is arranged at the ends of the screws remote from the ends thereof shown in the drawings, such device extending downwardly from a shaft similar to shaft 14 and positioned at a level somewhat higher than the Work screw 2. In other words, the device would appear somewhat as if the drawings are viewed upside down, the screws 1 and 2 being then interchanged.

What is claimed is:

1. A needle bar mechanism for drawing fibres comprising a plurality of needle bars, a work screw for imparting translatory motion to each of said needle bars in one direction during a working stroke, a return screw for imparting translatory motion to the needle bars in the opposite direction to said one direction during a return stroke, means for transferring said needle bars from one of said screws to the other of said screws during a transfer stroke, a guide member, a first surface defined upon said guide member and disposed so as to exert a guiding action upon said needle bars during a transfer stroke, a braking member, and a second surface defined upon said braking member and disposed so as to exert a braking action upon said needle bars during a transfer stroke, said first and second surfaces being arranged to simultaneously cooperate with the same needle bar over at least a portion of the transfer stroke, and resilient means for applying forces independently to the guide and braking members, said guide and braking members, each including a pivotal lever.

2. A mechanism according to claim 1, wherein said first surface is substantially flat and said second surface includes a flat portion and a curved portion, said curved portion extending at least adjacent the end of the second surface and being shaped to provide a progressive braking action.

3. A mechanism according to claim 2, wherein the said first surface and said flat portion of said second surface are of relatively small width, and the said curved portion is of greater width than the said first surface and flat portion.

4. A needle bar mechanism for drawing fibres, which includes a plurality of needle bars, a work screw for imparting translating motion to each of said needle bars in one direction during a working stroke, a return screw for imparting to each needle bar translatory motion in the opposite direction to said one direction during a'return stroke, means for transferring each needle bar from the end of one of said screws to the beginning of the other of said screws during a transfer stroke, a guide lever, means pivotally mounting said guide lever, first resilient means applying a biassing force to said guide lever, a substantially flat first surface of relatively small width defined upon said guide lever and arranged to exert a guiding action upon each needle bar during at least a portion of its transfer stroke, a braking lever, means pivotally mounting said braking lever, second resilient means applying a biassing force to said braking lever, a substantially flat second surface portion of relatively small Width defined upon said braking lever, and a curved second surface portion of increased width defined upon said braking lever and arranged to exert a progressive braking force upon each and simultaneously with the guiding action exerted by said guide lever.

References Cited by the Examiner UNITED STATES PATENTS 1,484,567 2/1924 Ryan 19-129 2,938,240 5/1960 Hill 19129 FOREIGN PATENTS 739,378 10/1932 France.

895,870 11/1953 Germany. 642,143 8/1950 Great Britain.

needle bar during at least a portion of its transfer stroke 15 ROBERT R. MACKEY, Primary Examiner.

Claims

1. A NEEDLE BAR MECHANISM FOR DRAWING FIBRES COMPRISING A PLURALITY OF NEEDLE BARS, A WORO SCREW FOR IMPARTING TRANSLATORY MOTION TO EACH OF SAID NEEDLE BARS IN ONE