GB2183609A - Separator for piliferous fabric sheets - Google Patents

Abstract

Cut pieces of nonwoven fabric with a pile (2), are separated from a stack thereof by means of a support (4) extending above the stack, levers (8) pivotally mounted on the support, a separator head (5) having fabric engaging hooks (17) and pivotally mounted at (6) on the levers (8), and a piston/cylinder assembly (13, 14) pivotally mounted at (7) on the separator head (5), to rotate the head (5) anticlockwise from the position of Figure 1 to engage the hooks (17) progressively with the uppermost sheet (31) and turn the levers (8) to lift the head (5) and the engaged sheet (31). A separator slide (3) is inserted between the lifted sheet (31) and the stack for removal of the sheet (31). <IMAGE>

Description

SPECIFICATION Sheet material separator This invention relates two a device for separating sheets of material in a stack, such a nonwoven fabrics with a pile surface, e.g. cord and velvet.

Many devices for separating nonwoven textile fabrics are known. However none ofthe known devices isablereliablytoovercomethehigh adhesiveforces which occur between stacked sheets of nonwoven fabrics with a pile surface. For example, a device is known which comprises a rolling member provided with inclined needle points which are rolled overthe first layer ofthe stack from a stack edge at a higher speed than that at which the actual rolling member moves. The movement is transmitted via a gearwheel-toothed rack connection, the roller being mounted in a horizontal sliding carriage. The device also has a separating slide which is inserted between the stack and the separated layer of the stack.

The disadvantage ofthis device is that there is a risk of considerable damage being causedtothefab- ric as a result of the differeing speeds ofthe rolling member's feed and rotary motion. Another known device has a support, a separating head and awork- ing cylinderfordriving the head. This devicesimu- Itaneously operates as both a separating device and a take-up device. Two of these devices are provided, arranged on opposite sides ofthe stack. Each separating head bears a row of needles which points towards the edge ofthe stack and forms an acute angle with the top layers. This angle must be less than 45", otherwise the device will not operate at all.The separating head also serves as a holding-down member, as it bears down as a pressure point on the fabric layer.

This device has the disadvantage of being unreliable, owing to the combination ofthe separating and taking-up operations. There is also a risk, inherent in the device, of the fabric being damaged or overstretched, as the layer which isto be taken up hasto be stretched between the two separating heads.

An object of the invention is to provide improved reliability when separating sheets in a stack, e.g.

textile cut-to-size pieces with a pile surface, without the nonwoven fabric being damaged or pulled.

According to the invention there is provided a de viceforseparating sheets of material in a stack, comprising a support for extending above the stack, an arm pivotally mounted on the support, a rotary separating head pivotally mounted on the arm, the head having thereon peripherally disposed meansforengaging the sheet material to pick up the uppermost sheet thereof, drive means connected to the head to move it across the uppermost sheet of the stack such thatthe head rotates to engage progressively said engaging meanswiththe uppermostsheet and the arm rotates relative to the support to lift the head and the engaged sheet from the stack, and separating meansforinsertion between the lifted sheetandthe stack.

In a preferred embodimentofthe invention,the separating head is provided with two pivots, the first pivot being arranged centrally and connected to the support via levers, while the second pivot is disposed in the top corner opposite the separating slide and is a point ofapplication forthe working cylinder, which is also connected to the support. A holdingdown member is fitted to the support quite a distance in from the separating head, and the separating slide is mounted with a rocker. The levers are one-armed levers and are rotatably secured at their upper end to the support. Aspiring connection to the support is formed in the upperthird of the levers.

When in the starting position, the levers are slightly inclined in the direction ofthe stack edge. Itisadvis- ableforthe spring connection to be a pliant tension spring. Stopsforthe levers are arranged next to this spring on the support. According to the invention, a torsion spring is secured to the lower pivot, the legs of which spring bear against a lever orthe actual separating head.

The working cylinderforthe separating head is pivotably arranged on the support, and the separating head is provided with small hooks,thetipsof which point in the direction ofthefront edge ofthe stack, with which they form an angle of between 70 and 90 . Afurther characteristic feature of the invention is the arrangement of a stripping brush in front of the stack and between the latter and the rocker.

The actual rocker is rigidly mounted and provided at its front end with a slider and at its rear end with an inclined plane. The separating slide is also provided withaslider,which is arranged oppositethe inclined plane and consists of a resilient material.

The method according to the invention is characterised bythefollowing operating steps: rolling back the edge ofthetop layer, raising this layer, separating the layerfrom the stack, depositing the layer, unrolling the edge and raising the top layer from the stack.

The device and the method according to the invention havetheimportantadvantageofenabling pieces of cord or velvet, etc. to be reliably separated from the stack. The material for sewing is never damaged. This is also dueto the fact, interalia, that the device operates with ascertain resilience, as the stack acts as a drive component. This also means thatthe other drive components do not have to meet any particularly high requirements as regards accurate measurements, as is the case with drive units which work on a purely mechanical basis.

Nor does the device according to the invention allow any displacement of the pieces to be separated with respect to the stack, and the next piece is not raised with the one above.

Owing to its resilience, the device can be used for different sewing material thicknesses, without the pieces having to be exchanged.

The invention is described in detail in the following with reference to an embodiment. In the accompanying drawings: Figure 1 is a view of the device according to the invention in the starting position; Figure2 is a view when it is in the operating position; and Figure 3 is a perspective drawings of the separating head.

The device according to the invention consists es sentiallyofthe opening device 1,the stack2 which is to be separated and the separating slide 3. All the operating components which are to be moved and which require a drive are provided in a known manner with working cylinders, which are nottherefore shown in detail.

The opening device 1 is secured as a whole to a support 4. A separating head 5 is provided with two pivots 6,7, the first pivot 6 being arranged centrally, whilethe second pivot7 is disposed inthetopright- hand (Figure 1 ) corner of the separating head 5. This isthecornerfacing away from the separating slide 3.

The connection betweenthesupport4andtheseparating head 5 is formed by levers 8. These levers 8, one of which is secured to the front and oneto the rearsideofthe support4, are mounted on the bearing bolt9 of the pivot 6 and are rotatably connected attheirtopendstothesupport4.Afurtherconnec tion to the support4 isformed bytension springs 10, which are associated with the levers 8 respectively, each tension spring 10 advantageously being a pliant spring, engaging in the upperthird ofthe levers 8.Also, an adjustable stop 11 is provided for each lever 8.

The second, top pivot 7 is connected to the piston rod 13 ofa working cylinder 14via a connecting part 12. The working cylinder 14 is itself pivotably secured to the support4. As can be seen in particular from Figure 3, a torsion spring 15 is mounted on the bearing bolt 9, the legs ofwhich spring are supported art a lever8 or at the front ofthe separating head 5.

In the present embodiment the separating head 5 is provided with small hooks 16, which are engaged in a plurality of rows close to one another and the tips 17 of which are bent in the direction of edge 18 ofthe stack 2, with which theyform an angle of between 70 and900.Aholding-down member 19 is secured to the front end ofthe support 4 at a certain distance from the separating head 5. This can be a simple machined metal strip of an appropriate thickness and bent at the stack side. The lower surface is prov idedwitha plurality of pins 20.

The device operates with a separating slide 3, which is known perse. However in the present case it is mounted on a rocker 21. It consists of a resilient material and its rear side comprises a slider 22, which points downwards. The rocker 21 swivels about a bearing point 23, which is held by a frame part 24. This frame part 24 also supports an adjustable stop 25 forthe rocker21. At the front end ofthe rocker 21 there is a further slide 26, which supports the separating slide 3, while atthe rear end ofthe rocker21 there is an inclined plane 27 on which the slider 22 can slide. This arrangement enables the rocker 21 to be automatically controlled.

Astripping brush 28 is arranged in front ofthe front stack edge 18 such that, when in the starting position, its bristles 29 are directly above the top layer of the stack 2,which they slightly overlap.

The levers 8 andtheseparating head Saredim- ensioned such thatthe tips 17 of the small hooks describe a hypocycloidal motion. For this purpose the length ofthe levers 8, i.e. the distance between the lower pivot 6 and the upper pivot 30 the support4, is considerably greaterthan the distance between the two pivots 6 and 7 ofthe separating head 5.

The device operates according to the following method; The starting position required for opening the stack 2 is shown in Figure 1. The holding-down member 19 and the separating head 5 are placed on the top cut-to-size piece 31 of the stack 2. The levers 8 are slightly inclined in the direction ofthe stack edge l8andthetipsl7ofthesmallhooksformanangleof between 70" and 90" with the surface of the stack, i.e.

this angle is steep. A movement is imparted to the separating head 5 via th e wo rki n g cylinder 14, so as to causethe upper pivot 7 to move overthe lower pivot 6. The tips 17 of the small hooks are therefore applied one afterthe other to the top cut-to-size piece 31 and roll it back from the edge. The movement des cribed by the tips 17 ofthe small hooks is a hypocycloid, and the first phase ofthe path, through the inclined position of the levers 8, enables the separat ing head 5to roll for a fairly long distance overthe top cut-to-size piece 31, before the second phase of the path commences, during which the top cut-tosize piece 31 is raised.During both phases the holding-down member 19 prevents the top cut-to-size piece31 from being displacedorstrained,whilethe stripping brush 28 holds backthesecond piece, so that it is not raised withthetop one. Thus, the piece 31 is lifted by the head 5 as shown in Figure 2.

The extent ofthe forces acting on the top cut-tosize piece 31 between the holding-down member 19 andtheseparating head5isdeterminedbytheten- sion spring 10, whilethe starting position ofthe levers 8 is determined bythe stop 11.

Also, as shown in Figure 2, as the stack 2 is opened (i.e. the top piece 31 is lifted),theseparating slide 3 is inserted into the stack2 by its working cylinder4and separates the piece 31 entirely from the stack 2. In order to prevent the separating slide 3 from catching the edge ofthe stackwhen being inserted, the tips of the separating slide are raised over it by the rocker 21. Once the slider 22 has reached the end of inclined plane 27, the separating slide 3 is again in a horizontal position. Afterthe separating slide 3 has been inserted, the top cut-to-size piece 31 is unrolled i.e.

following the same path along which it was rolled up, and the hooks releasetheirhold. The holding down member 19 andtheseparating head 2 are moved away and the separated cut-to-size piece 31 can be taken up from the separating slide 3 by known means.

The operation isthen repeated.

Claims (20)

1. Adeviceforseparating sheets of material in a stack, comprising asupportforextending abovethe stack, an arm pivotally mounted on the support, a rotary separating head pivotally mounted on the arm, the head having thereon periphera!iEl dispose ' meansforengaging the sheet material to pickupthe uppermost sheet thereof, drive means connected to the head to move it across the uppermost sheet of the stack such that the head rotates to engage pro gressivelysaid engaging means with the uppermost sheet and the arm rotates relative to the supportto liftthe head and the engaged sheet from the stack, and separating means for insertion between the lifted sheet and the stack.

2. A device according to claim 1 wherein the head has a curved peripheral surface,and said engaging means comprises a plurality of hooks disposed around said surface.

3. Adevice according to claim 1 or 2 including a holding-down member attached to said support and which is operative to hold down one end ofthe uppermost sheet of the stack.

4. A device according to any preceding claim wherein the arm includes first and second spaced apart levers pivotally mounted on the support on a common pivot axis, and a shaft defining a second pivot axis about which the head is pivotally mounted, and said drive means comprises a piston and cylinder assembly pivotally mounted at one end and on the support and pivotally mounted on the other end and on the head about an axis disposed eccentrically and above said second pivot axis.

5. A device according to any preceding claim including spinning means urging said head to rotate about the second pivot axis in a predetermined direction.

6. A device according to any preceding claim including adjustable stop means for said arm, and spring means urging the arm against the stop means.

7. A device according to any preceding claim including meansfortending to inhibit lifting ofthe next uppermostsheet upon lifting ofthe uppermostsheet of the stack.

8. A device according to any preceding claim and including the stack.

9. A device according to claim 8 wherein the stack comprises sheets of nonwoven textile fabric.

10. A device according to claim 9 wherein said fabric has a pile surface.

11. A deviceforseparating sheets of material in a stack, substantially as hereinbefore described with reference to the accompanying drawings.

12. A deviceforseparating nonwoven textilefabrics from a stack, preferably of nonwoven fabrics with a pile surface, such as cord, velvet, etc., by means oftake-up devices and one opening device and separating slide per stack, the opening device consisting of a support, the separating head and a working cylinder, and the separating head being provided with small hooks, characterised in thatthe separating head is provided with two pivots,thefirst pivot being arranged centrally and connected to the support via levers, which the second pivot is disposed in the top corner opposite the separating slide and is a pointofapplicationfortheworking cylinder, which is also connected to the support, that a holding-down member is fitted to the support quite a distance in from ofthe separating head, and in that the separating slide is mounted with a rocker.

13. A device according to claim 12,characterised in that each lever is a one-armed lever, which is rotatably secured at the upper end to the support, and in that a spring connection with the support is also formed in the upperthird.

14. A device according to claim 12 or 13, characterised in that, when in the starting position, the levers are slightly inclined in the direction of the separating slide.

15. Adeviceaccordingto claim 14,characterised in thatthe spring connection is in each case a pliant tensionspring,nexttowhicha respectivestopfor each lever is secured to the support.

16. A device according to claim 12, characterised in thatthetips ofthe small hooks point in the direction of the stack edge, with which they form an angle of between 70 and 90 .

17. A device according to claim 12,characterised in that a stripping brush is arranged between the stack and the rocker.

18. A device according to claim 12,characterised in thatthe rocker is provided at its front end with a slider and at its rear end with an inclined plane and is rigidly mounted.

19. A device according to claim 12, characterised in thatthe separating slide consists of a resilient material and is provided with a slider.

20. A method for separating nonwoven textile fabrics from a stack, in which the stack is opened and the top layertaken up by different operating components, characterised by the following operating steps: rolling backtheedgeofthetoplayer, raising this layer, separating the layerfrom the stack, depositing the layer, unrolling the edge, and raising the top layer from the stack.