US3813866A

US3813866A - Gripping means for doffing yarn packages

Info

Publication number: US3813866A
Application number: US00221864A
Authority: US
Inventors: G Goldammer; E Grimm; E Egli
Original assignee: Schubert und Salzer Maschinenfabrik AG
Current assignee: Rieter Ingolstadt Spinnereimaschinenbau AG
Priority date: 1971-02-05
Filing date: 1972-01-31
Publication date: 1974-06-04
Anticipated expiration: 1991-06-04
Also published as: GB1385334A; IT947189B; FR2124465A1; ES399457A1; FR2124465B1; DE2105344A1; NL7201491A; CH529854A

Abstract

Yarn packages wound on tubes by ring spinning machinery are doffed by an arm which is lowered until a ring carried thereon encircles the tube end portion. The ring has a gap and the two free ring ends are positively moved toward each other across the gap to contract the ring to embrace the tube. A separate lever arm is connected to each ring free end. The two levers are disposed substantially parallel and are normally wedged apart to maintain the ring ends in spread condition to receive a tube. Electromagnetic drive means effect movement of the levers together to contract the ring and grip a tube end. After the arm is raised, the levers are spread to release the tube and a plate above the ring presses the tube quickly out of the ring.

Description

United States Patent [191 Goldammer et al.

[451 June 4,1974

[ 1 GRIPPING MEANS FOR DOFFING YARN PACKAGES [75] Inventors: Georg Goldammer, Friedrichshofen;

Eberhard Grimm, Ingolstadt; Emil Egli, Windisch, all of Switzerland [73] Assignee: Schubert & Salzer Maschinenfabrik Aktiengesellschaft, lngolstadt, Germany [22] Filed: Jan. 31, 1.972

[21] Appl. No.: 221,864

[30] Foreign Application Priority Data Feb. 5, 1971 Germany 2105344 [52] US. Cl 57/52, 294/67 BC [51] Int. Cl ..D01h 9/08 [58] Field of Search 57/52, 53, 54; 242/41; 294/8722, 87.24, 67 BC [56] References Cited UNITED STATES PATENTS 1,463,479 7/1923 Miller 57/52 2,862,756 12/1958 Larson 294/67 BC X 2,962,856 12/1960 Ingham, .Ir 57/52 3,053,561 9/1962 Hamel 294/8722 3,307,340 3/1967 Nishii et al 57/53 3,398,522 8/1968 Niederer 57/53 3,408,806 11/1968 Fess et al. 57/53 3,442,072 5/1969 Gillono et a1. 57/53 3,566,597 3/1971 Para 57/53 3,633,959 1/1972 MCCOIlOugh et al. 57/52 X FOREIGN PATENTS OR APPLICATIONS 1,012,789 12/1965 Great Britain 57/53 Primary Examiner.lohn W. l-Iuckert Assistant Examiner-Charles Gorenstein Attorney, Agent, 0r'Firm-Robert W. Beach; Ms. R. M. Van Winkle 5 7 ABSTRACT Yarn packages wound on tubes by ring spinning machinery are doffed by an arm which is lowered until a ring carried thereon encircles the tube end portion. The ring has a gap and the two free ring ends are positively moved toward each other across the gap to contract the ring to embrace the tube. A separate lever arm is connected to each ring free end. The two levers are disposed substantially parallel and are normally wedged apart to maintain the ring ends in spread condition to receive a tube. Electromagnetic drive means effect movement of the levers together to contract the ring and grip a tube end. After the arm is raised, the levers are spread to release the tube and a plate above the ring presses the tube quickly out of the ring.

2 Claims, 4 Drawing Figures GRIPPING MEANS FOR DOFFING YARN PACKAGES BACKGROUND INVENTION 1. Field to which invention relates The invention relates more particularly to a gripping means for doffing .yarn packages on ring spinning and ring doublingtmachines, comprising an annular gripping or clamping element adapted to engage the core of the yarn package.

2. The prior art In accordance with a previous proposal an elastic, closed gripping ring was to be used for doffing yarn packages on ring spinning and ring doubling machines (hereinafter referred to as ring spinning machinery). This gripping ring was moved downwards onto the end of the package core and changed in size by pressure acting from above on the ring so that the ring gripped the periphery of the core (see British patent specification 1,012,789). The reliabilitypf operation of this gripping ring, which was to be provided on a doffing arrangement travelling uninterruptedly along the machine, was however insufficient because, owing to its necessarily very elastic or resilient construction, it was not possible to achieve a sufficiently positive action. In the case of such yarn package doffing devices, only fractions of a second are available for engaging the core or tube and part of this time is required, in case of pressure acting from above on the ring, for initial stressing of the ring. The remaining time is not sufficient to reduce the size of the ring to such an extent that the core or tube is grasped with sufficient force for doffing. A further disadvantage of the previously proposed gripping ring is that the bore of the ring must be made very small and can only exceed the diameter of the end of the core by a slight amount in order to allow the ring to be rapidly pressed on the core or tube. The gripping ring can therefore only grasp the end of the tube when its diameter does not exceed the prescribed size and the spindle, on which the tube is mounted, is precisely vertical. If one of these conditions is not fulfilled, the core cannot enter the bore of the gripping ring.

In accordance with a still further prior proposal (see British patent specification 1,012,789) for a gripping element, use was-to be made of -a band which surrounded the upper end of the core and was drawn tight by a force acting on the end of the band. However, it is found that the force acting on the band is to a substantial extent taken up by overcoming friction and can only act with a certain time lag on the whole end of the core, so that such a gripping element cannot properly engage the end of the core in the time which is actually available.

SUMMARY OF INVENTION One aim of the present invention is to provide an annular gripping element which is engageable with the outer periphery of the core of a yarn package and which avoids the above-mentioned disadvantages.

The present invention is a gripping or clamping device for doffing yarn packages on ring spinning machinery comprising a gripping snap ring adapted to engage theouter surface of the core of such a yarn package and means connected with ends of the ring at'opposite sides of the ring gap for applying force to the ring for changing its diameter. The means for applying the force can be adapted to exert either a tension or a thrust force. In accordance with one particular embodiment of the invention the gripping ring comprises a number of secondary rings. In order to engage the whole of the outer peripheral surface of the core, the gaps in these secondary rings are circumferentially offset from one another. In accordance with another embodiment of the invention the interrupted ring comprises two ring segments and one end of each such segment is fixed at a stationary point. The two ends of the rings adjacent to the gap in the ring can be moved in relation to each other. By simultaneous movement of the ends toward each other, an accelerated contraction of the ring is brought about. The gripping action of the interrupted ring can be improved by making it of a flexible, non-elastic, band-like part which on its inner surface has an elastic coating. In accordance with a further feature of the invention, a solenoid is used to produce the thrust or tension forces. The bore of the gripping ring is closed in an upward direction by a pressure plate which can be moved vertically. This makes possible an accelerated ejection of the core or tube with the rest of the yarn package from the gripping ring.

LIST OF SEVERAL VIEWS OF DRAWINGS Further details of the invention will now be described with reference to the accompanying drawings.

FIG. 1 is a diagrammatic bottom plan of a gripper arm showing the device of the invention.

FIG. 2 is a longitudinal section along the line II-II of FIG. 1.

FIG. 3 is a plan of a two-piece gripping ring.-

FIG. 4 is an exploded top perspective of a gripping element made up of several secondary rings.

DESCRIPTION OF PREFERRED EMBODIMENTS The gripping arm shown in FIGS. 1 and 2 is part of a doffing device which can travel along ring spinning machinery, that is to say a ring spinning or ring doubling frame. In many respects the doffing device can be of conventional construction, as described for instance in the above-mentioned British patent specification 1,012,789. The gripper arm 1 is actuated by a drive via a thrust rod 10. The drive can be as described in the same British patent specification and is therefore not described in detail.

In the head, which is provided with a centering plate 11, of the gripping arm I, a gripping or clamping ring 2 constituting a gripping or clamping element is mounted so as to be capable of moving. In accordance with the invention the gripping ring is an interrupted ring with

ends

21 and 22 adjacent to the interruption or gap. The gripping ring 2 includes a flexible nonelastic part 20 in the form of a band and an elastic lining or coating 20 fixed on the part 20. While the flexible part 20 is preferably in the form of a strip string, the elastic part 20' can be made of rubber, plastics material or another material increasing frictional engagement with the package core. If rubber is selected as a mate rial for the coating, it can be connected with the part 20 by vulcanisation for example.

To the

ends

21 and 22 adjacent to the gap in the gripping ring 2, two

levers

23 and 24 are connected, respectively, by means of

pins

230 and 240. The

levers

22 and 24 can pivot about

pivot pins

231 and 241 located intermediately of their ends, and their free ends opposite ring 2

carry rollers

232 and 242. In the rest position shown in FIG. 1, the rollers are caused to abut against each other by a compression spring 25 acting on the lever arms on the side of

pivots

231, 241

opposite rollers

232, 242. Such roller abutment limits the opening of the gripping ring 2. Above the rollers 232 and 242 a bifurcated lever 3 is provided which can pivot about a pin 30, and a wedge-shaped downwardly inclined projection 31 located on the side of pin 30 opposite the lever furcations is arranged directly in front of the

rollers

232 and 242. The other, bifurcated, end of the twoarmed lever 3 is connected with a drive part 32, which is connected with a rod 33 guided in the housing of the gripping arm 1 and capable of being moved vertically through the rod 33 by a solenoid 12. A compression spring 34 encircling the rod 33 and engageable with a collar on the lower rod end reacts against the shell of the gripping arm 1 to press the rod 33 and the drive part 32 normally downward thereby holding wedge 31 out of engagement with

rollers

232 and 242. The upper end of the gripping opening or bore of the gripping ring 2 is normally closed by a vertically movable plate 4 which is arranged in the head of the gripping arm 1 and pressed toward ring 2 by a spring 40.

n downward movement of the thrust rod 11), the gripping arm is lowered together with the centering plate 11 and the gripping ring 2 over the core or tube of a yarn package, so that the core comes to lie in the bore of the ring 2. The core which comes to extend through the opening of the gripping ring abuts against the abutment plate 4 at the top end of the bore and presses the plate away from the gripping ring 2 against the force of the spring 40. Simultaneously the solenoid 12 is actuated so that the rod 33 is attracted by it and moves upwards together with the drive part 32 in a vertical direction.

The pivoting movement of the bifurcated lever 3 effected thereby causes the wedge-like end 31 to be thrust between the

rollers

232 and 242 so that the latter are pushed apart against the force of the spring 25. The

levers

23 and 24 pivot about the

pins

231 and 241 and now exert a tension force on the

ends

21 and 22 adjacent to the gap in the gripping ring 2 so that the ends are moved towards each other. The gripping ring 2 is thus caused to contract and becomes pressed against the outer periphery of the tube 5.

When the core or tube 5 and the yarn thereon has been drawn from the spindle owing to the upward movement of the thrust rod after pivotal movement of the gripping arm 1, the solenoid 12 is deactivated by a switch which is not shown in the drawing and the rod 33 is released by it. Accordingly the compression spring 34 is able to press the rod 33 with the drive part 32 downwards, so that the latter and the bifurcated lever 3 with its wedge-shaped end 31 can return into their initial positions. Owing to the pressing force of the spring 25 the

levers

23 and 24 swing about the

pins

231 and 241 and move the

ends

21 and 22 adjacent to the interruption in the ring away from each other. The tube or core 5 is now able to drop out of the opened gripping ring 2. Ejection of the core 5 is aided by the plate 4 which snaps back towards the opening of the gripping ring owing to the force exerted by the spring 40.

In the case of the embodiment shown in FIG. 3 the gripping ring consists of two ring halves or

segments

26 and 27, whose adjacent ends 260 and 270 are attached at the pivot points 261 and 271 which are stationary with respect to the housing or shell of the gripping arm.

The levers 23 and 24.are joined in a fixed manner with the opposite ends 262 and 272 of the two

ring segments

26 and 27, adjacent to the variable gap in the composite ring. The

levers

23 and 24 are operated in the manner already explained so that the

ring segments

26 and 27 are drawn together by the tension forces acting at their

ends

262 and 272 adjacent to the interruption in the ring and the ring segments accordingly grip the upper end of the core or tube 5 lying between them.

It is naturally possible for the ends 260 .and 270 to be anchored in a manner different to that shown. Thus, for example, both ends can be anchored at a single point and in this case the ends 260 and 2'70 would overlap or be connected by means of resilient intermediate members.

In another embodiment of the invention the gripping ring or element in accordance with the invention comprises two superposed interrupted secondary

gripping rings

28, 29 of elastic material arranged so that the interruptions in them between their respective ends (281, 282 and 291, 292) are circumferentially offset (see FIG. 4). The interrupted

secondary rings

28 and 29 are connected with each other by interrupted

intermediate rings

28, 29 of non-elastic material in the manner indicated by connecting lines A. In order to make clear the connection of the individual secondary rings the superposed secondary rings are shown in exploded relationship in FIG. 4. It will be seen that the end 281 adjacent to the interruption of the gripping ring 28 is connected with the intermediate ring 28' while the end 282, adjacent to the interruption, is connected with the intermediate ring 29'. On the other hand, the end 291 adjacent to the interruption in the ring of the ring 29 is connected in a fixed manner with the intermediate ring 29 and the end 292 adjacent to the gap is connected in a fixed manner with the intermediate ring 28. A pressing force acting at the ends adjacent to the interruptions of the gripping

rings

28 and 29 can be produced by means of gear wheels (which are not shown) for example. Such gear wheels are connected respectively with the

ends

282 and 292 in a fixed manner and mesh with a rack which can be moved along the longitudinal axis of the gripping arm. If the gear wheels are twisted by means of the respective racks in a direction indicated by the arrows P and P the open ends 282, 292 will be moved, owing to the pressing forces acting upon them, towards the

ends

281 and 291, respectively. However, simultaneously, the

ends

281 and 291 will be moved towards the

ends

282 and 292, since the pressing forces engaging the end 282 will be transmitted via the intermediate ring 29' to the end 291 and the pressing forces acting on the end 292 will be transmitted via the intermediate ring 28' to the end 281.

The invention has been described with reference to a travelling cop doffing device. It can, however, also be used successfully with stationarily arranged doffing devices.

We claim:

l. A gripping device for dofi'mg yarn packages wound on tubes on ring spinning and ring twisting machinery comprising an interrupted gripping ring engageable with a yarn package tube end portion and having two spaced free ends, and drive means connected with said ends for positively moving said ends towards each other and thereby contracting said gripping ring for pressing it against the outer suface of such tube, said interrupted with a yarn package tube end portion, said interrupted ring comprising a flexible nonelastic annular band and an elastic lining fixed on said band and having two spaced free ends, and drive means connected with said ends for positively moving said ends towards each other and thereby contracting said gripping ring for pressing it against the outer surface of such tube.

jg ggg UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,813,866 Dated June 4, 1974 Inventor(s) Georg Goldammer, Eberhard Grimm and Emil Egli It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Title page; section'75 should read:

--Georg 'Goldammer, Friedrichshofen, West. Germany;

Eberhard Grimm, Ingolstadt, West-Germany; Emil Egli, Windisch, Switzerland-- Signed and sealed this 10th day of December 19%.

(STEAL) Attest:

HcCOY (31830 JR. C, 1*IARt32EMZI, DANE? Arresting Officer Commissioner of Patents

Claims

1. A gripping device for doffing yarn packages wound on tubes on ring spinning and ring twisting machinery comprising an interrupted gripping ring engageable with a yarn package tube end portion and having two spaced free ends, and drive means connected with said ends for positively moving said ends towards each other and thereby contracting said gripping ring for pressing it against the outer suface of such tube, said interrupted gripping ring including a plurality of annular interrupted secondary ring sections, said ring sections being superposed and interconnected and the interruption of each said secondary ring section being circumferentially offset from the interruptions of the other ring sections.

2. A gripping device for doffing yarn packages wound on tubes on ring spinning and ring twisting machinery comprising an interrupted gripping ring engageable with a yarn package tube end portion, said interrupted ring comprising a flexible nonelastic annular band and an elastic lining fixed on said band and having two spaced free ends, and drive meaNs connected with said ends for positively moving said ends towards each other and thereby contracting said gripping ring for pressing it against the outer surface of such tube.