DE1303136B - - Google Patents

Description

The invention relates to a storage device for permeable pieces of tissue or the like from a stack by means of a blow nozzle arrangement.

Stacks of pieces of fabric occur in clothing manufacture and in laundry businesses, for example when cutting a multi-layer pile of fabric or with automatic ironing machines. Here, the pieces of fabric in the pile often have to fi "r a subsequent operation, for example for sewing or folding, again individually from the stack be removed. To work away from a pile at all, an automatically continuous one To be able to carry out production, it must be ensured that only a single piece is gripped with certainty becomes, because if two or even three pieces are randomly conveyed, the subsequent production line is immediately brought into disorder or individual production machines are even destroyed can.

The object of the invention is therefore to create a device for automatic operation, which even with difficult to handle materials, such as highly permeable, fine fabrics, more or less partially permeable, patterned fabrics, knitted fabrics or the like, especially in pile fabrics, a secure gripping and forwarding of only a single piece of tissue or fabric at a time guaranteed.

Machines for removing individual sheets from a stack are known from the paper industry, in which the stack is blown with air from the side and the top sheet is at the same time by means of Suction air is lifted off. Such devices are not for separating pieces of fabric suitable because these stick together more strongly than sheets of paper due to their higher surface roughness and the suction force acting from above is insufficient due to the air permeability of the pile of fabric, lift the top piece of fabric. There are also devices for separating sheets of paper known (e.g. from the German Auslegeschriften 1 060 874 and 1 065 430), in which from a nozzle air exits, which by means of a to the Ausirittsrichtung deflected the air essentially vertical baffle perpendicular to the exit direction when the nozzle is arranged together with the guide plate above the paper stack. By between the guide plate and the top paper

arc flowing air is in the intervening Space creates a negative pressure, due to which the top sheet of paper are raised can.

Surprisingly, it has been shown that this

■ The principle can also be used to separate pieces of fabric from a stack. Here, however, the function differs from that when separating sheets of paper.

To solve the specified issue is therefore

a lifting device for permeable pieces of tissue or the like from a stack by means of a blow nozzle arrangement characterized in that above the stack a nozzle plate counter to its own weight effect slidable over the top of the stack

surface is held, wherein the effective area of the nozzle plate a substantial part of the stack surface and the nozzle cross section occupies a substantial part of the area of the nozzle plate. By means of the lifting device according to the invention, almost any type of highly flexible fabric parts of practically any shape can be lifted from a stack without having to take into account the felting of the edges during the cutting process; In this case, only the uppermost piece lifted off is properly picked up, that is to say, without taking along the remaining pieces below, by a removal device or further conveying device and can be fed to a subsequent operation. The air blown out of the nozzle is fed to the piece of fabric from above and only partially flows between the nozzle plate and the topmost piece of fabric of the stack. The other part of the blown air flows through the top piece of fabric, escapes under it to the side and lifts it from below, while in contrast to this, when separating a stack of paper sheets, the air comes from the side under the paper sheets to be lifted. No more highly compressed or compressed air is required for this, but it is possible to work with essentially uncompressed air, the total pressure of which is below 0.35 kp / cm ² and is generated with commercially available fans, for example household vacuum cleaners.

With the lifting device according to the invention, a single piece of fabric from a stack can through the action of two different but interacting effects can be resolved and separated. A lifting force acts on the top piece of fabric so that a small part of it is at an angle to the Face of the stack protrudes, while air is at an angle against and through the protruding part flows without the protruding piece on the

3 4

Pushes back the stack. The air thus passes through a nozzle 16 on which is loosely displaceable

the porous material between the top piece and with a nozzle plate 20 is located. Below the

the pile. In this way between the nozzle and plate is a table 21 on which

the topmost piece and the stack generated little air - a stack of pieces of fabric 22 rests. The diameter pressure and the flow are sufficient, a lifting of the 5 of the nozzle can be about 41 mm and the fabric -

to prevent the second piece. In contrast, the pieces can in Fig. 1 a length L of about

the top piece from the second piece upwards are 46 cm.

upscale. If this effect is along a full the air flows in the direction of arrow 26 after

Arc is generated, takes the piece of tissue below. Part A of the topmost panel 22 'becomes

a shape that is impressed by the air in cross section of a volcanic crater io, and it is imagined

resembles. Cone 27 of stagnant air is relatively high

The aforementioned two effects become preferential printing.

wisely achieved by forced air, being part of the When the piece of fabric of the action of the nozzle and

Air flowing at high speed so as to expose one of the guardrail occurs initially

Zone of lower pressure arises around the mentioned 15 the following: First, the air 27 presses down

small part of the fabric in the protruding position towards the pile. Next, the plate 20 rises

bring, while the other part of the air, preferential something, leaving a narrow lateral passage between

wise at the base of this part, against and through which the plate 20 and the piece of fabric 22 'is formed. as

protruding part flows. This third part of the air flows into air at high speed wegi is slower and therefore has a higher 20 lateral direction through .. η narrow intermediate

Pressure. Whenever the stroke effect df ″ flows rapidly, as shown by the arrow 28;

With the lower pressure air the flattening and there is a negative pressure, which is a part b of the piece of fabric

pushing back effect that strives to flow more slowly - to lift. Outside the nozzle 16 slowed down

Exceeds the air of high pressure, the first fast flowing air remains, whereby you

standing part of the tissue is erected and the pressure rises and on the blow nozzle plate

further pressure directed by air is exerted in the desired manner, which transforms them into a

flows. a certain distance from the pile of fabric. Fourth

The desired effects can be achieved by means of a central, ring-shaped part C of the fabric

umpteen air duct and a piece assigned to it and stands like a wall at an angle

Blow nozzle plate or also achieved separately 30 to the surface of the stack in the space between

will. see the pile and the plate. Fifth, flows

In advantageous developments of the invention, while the middle part C rises at the same time. Air 30

the nozzle plate with flexible side parts against and through the central part C forming

be provided, or the outer areas of a right-hand piece of fabric from an air zone 27 and 29 relative

Angular nozzle plate can be curved. 35 low speed and high pressure. The

Furthermore, in a manner known per se, the highest blowing pressure can be applied to the base, that is to say the

nozzle plate exerted a further conveying device downstream of the lowest area of the Tciis C of the substance j, so

be switched. that the leverage or movement that the

The invention is striving to push back on the stack with reference to preferred parts C , mini-guide forms explained in more detail below. It is 40 times. Sixth, there is an increase in pressure under the topmost piece of fabric, which causes the slack and

F i g. 1 shows a simplified sectional view of a softened piece in a considerable area 40

preferred embodiment of the invention, bends and lifts, whereas the next piece below

F i g. 2a to 2c perspective views show the effect of this weak pressure downwards different embodiments of the invention is pressed. In this way, an adequate Blow nozzle plate, expanded air pocket 39 are formed and the Rci-

F i g. 3 a and 3 b a side and top view of a force fit between the top piece 22 '

Embodiment with a curved blow nozzle and the stack 22 can be greatly reduced,

flat, the seventh creates turbulence when the rapid air

F i g. 3 c is a perspective view of the flow being slowed down at 29. This will make that

F i g. 3 a and 3 b similar embodiment, piece of fabric 22 'caused to flutter at 31 and it

F i g. 4 and 5 show a side view and a plan view, respectively, shafts 33 which run outwards are produced

an embodiment of a removal device, loosen the piece and its connection with the stack

in which the nozzle plate according to FIG. 2b used loosen up. The forces that affect the protruding part of the

is, 55 middle part C and form the air pocket 39, practice

F i g. Figure 6 is a vertical sectional view through an inward pull on the outer

second removal device, which is made in connection with parts of the piece that are

a lifting device according to the invention ver = opposite direction flowing air 28 after

is reversible, move inside. This contributes to the formation of the middle

F i g. 7 is a top view of embodiment 60 at part C. If the fabric isn't stretchy, wander F i g. 6, facing the edges of the piece inwards.

F i g. 8 is a perspective view of another. The gap H between the blow nozzle plate and the embodiment of the lifting device according to the stack is established under the effect of the air invention and current, since the plate 20 is freely displaceable and

9 is a vertical sectional view of the embodiment 65 being pressed against the table 21 by its weight,

8. Before the air flow begins, the plate is at rest

In the embodiment shown in Figure 1 on the stack and in use, the plate rises

if a fan with a vertical duct 14 is then about 1.26 cm above the stack. When the plate

hereby or through other measures it should be noted that the plate must not be pressed down in such a way that the uppermost piece of fabric is flattened. Rather, the plate must be at such a distance above the stack are located that the fabric wall C can form.

Furthermore, considerable air flow is very beneficial. For example, a single nozzle with a diameter of about 38 mm, which is fed the full capacity of an ordinary 1.5 horsepower household ^{vacuum cleaner that delivers about 0.1 kgf / cm 2 of} static air pressure when closed, is in the L. -agc, 35.5 x 76.2 cm towels easily lifted.

If the air pressure is increased considerably, some disturbing phenomena can occur: the increased pressure of the enclosed air tends to plane part C; the stack is then pushed in deeply under the nozzle 16, the friction between the top piece 22 'and the stack increases and an excessive amount of the relatively valuable air which is under higher pressure is lost if the blow nozzle plate is not tight against the stack is pressed. However, such pressure would be detrimental to the desired effect. Which pressure is particularly suitable. depends on many parameters, e.g. B. the Gcwebcyp and the dimension of the selected parts. What is essential to the invention, however, is that air from a rotating fan is very effective and can be produced much cheaper, including more highly compressed air which requires a compressor. In the case of the in FIG. 1, the pressure should under no circumstances rise ^{above 0.35 kgf / cm 2.}

To achieve separation in all directions, the outflow direction of the nozzle should at least run approximately vertically and the Lcitplattc should surround the nozzle.

FIG. 2 a shows an annular nozzle plate 20 'which extends outward in all directions by a distance which is somewhat smaller than the diameter of the nozzle. I'.mc such a plate is suitable for square pieces of fabric and the loosening effect extends about 25 cm radially in all directions.

In Fig. 2 b is a rectangular nozzle plate 20 " shown, whose long edges at the next point have a distance from the nozzle that is about corresponds to half the diameter of the nozzle, while the next distance corresponds to the short one Edges are about two and a half times the diameter. The long side of the plate becomes transverse to the long one Dimension of elongated pieces of fabric arranged. Because the flow paths of the fast flowing Air is shortest towards the middle of the long edges, most of the air flows there and has the greatest lifting effect there; also the air pockets 39 and the flutter in these directions are on biggest.

In Fig. 2 is the plate 20 "of FIG. 2b with thin, flexible, impermeable and smooth side parts 23 provided, the z. B. from one to the long Plastic folic attached to the edges. Between these side parts 23 and the fabric the turbulent air is trapped, so that the flutter is increased, while the side parts 23 offer only a slight resistance to the air flow.

The in F i g. 3 a and 3 h illustrated embodiment has a domed nozzle plate 50 with an air evacuating surface that is substantially runs parallel to the plane of the stack 54; an extension or a narrow edge 56 with a small Radius, for example 3.2 mm, is bent upwards. From a nozzle 58, air 60 flows at an angle downward over the top of the domed BlasdUscnplattc 50 to the edge 56. At the bottom of the curved part, a zone is formed relatively

ίο high pressure and the air flows through a slot 68. The air flowing through the lowest part of the slot 68 exerts a relatively high pressure onto the tissue and indent, while the Air through the top of the slot 68 at a higher rate Speed flows and lift part of the fabric to a protruding middle part is striving. This part of the air is deflected upwards by the curvature of the blower unit.

ao The air flowing over the surface of the arched blower plate moves upwards in the direction of the arrow 62 at the highest speed, as a result of which the negative pressure at the point 64 is increased. A small part 66 of the piece of material is therefore displaced towards the curved narrow edge 56 due to the curvature of the narrow edge! ^r t also room to take off for the part of 66 present. When the part 66 of the Stoifstück is lifted, there is resistance to the air flowing through the slot 68; the air must therefore flow in the direction of arrow 69 with higher pressure through the slot and through the part of the tissue exposed by the slot. This air, which is under higher pressure and penetrates the fabric, pushes the second piece of fabric away. The slot 68 is sufficiently narrow, e.g. B. 4.8 mm, so that the force exerted by the air under higher pressure is not able to push the part 66 back onto the stack 54, in particular also because the highest air pressure, as in that in FIG illustrated embodiment, occurs at the base of the standing portion 66 of the tissue, so that their hacking effect is smallest.

When in this embodiment the part 66 rises, it acts like a valve, which more air with higher Speed in the direction of arrow 62 flows. The thickness of the narrow rim 56 is preferably very large small, e.g. B. 0.38 mm, so that the tissue in close proximity and with the greatest force to the quickly irörncnden Airflow can increase. The separation of the top material gap from the second piece is also achieved the bending of the part 66 around the small radius of the narrow edge 56 is promoted.

F i g. 3 c is similar to F i g. 3 a and 3 b; the extension

However, 56 'is a surface of revolution around a vertical axis and the air flows radially in all directions and passes through a number of slots to lift the tissue.

In Fig. 4 and 5 a machine is shown which

is not the subject of the invention and which the lifting device of FIG. I contains. Can with her individual pieces are quickly removed from a stack 82. The stack 82 is on a table 80, which is slidably mounted with a leg 84 on a frame 86, so that its height is medium! a lifting device 87 can be adjusted. On a blow pipe 90 is a vertical air nozzle 81 Slidably mountable on which a blow nozzle

(ο

plate 92 is attached. The tube is connected to the outlet of a fan 96. The top piece of the stack was released by the effect described above and taken up by a suitable element will. This can be done, for example, by a revolving trigger cylinder 99 (which is also is not the subject of the invention) happened that over an edge 85 of the top piece of fabric 82 ' is mounted. Conveyor belts 102 run over the cylinder 98 and stand out from this at the point of attack with a conveyor belt 100.

The pieces have folded edges 93 on the opposite side of the removal device 98. If the negative pressure attracts the edge 85 of the piece of fabric, it is over a not shown in detail Knife edge pulled. The edge of the piece of fabric then bends around the edge. If the Moving the knife edge to the left, the piece of tissue is affected by the resistance it is moving opposed, pulled tighter around the knife edge. ao

4 and 5 it can be seen that the through the lifting and releasing device 88, 90 and 92 flowing air in practice the non-positive connection between the top piece and the second piece of the stack, and that the removal device 98 grips edge 85 and pulls the top layer over the stack. The with the uppermost I ^ ge connected next layer, peeled off without messing up the pile. To peel off the individual pieces at their edge to be able to, everyone must have a cin /. ac part of the> cimcm piece? " be withdrawn from the stack before the next piece is exposed to the removal device.

In Figs. 6 and 7 one of Fig. 4 is similar Device for receiving towels shown, which in turn is not the subject of the invention is. A hollow cylinder 105 connected to a vacuum source is rotatably supported in bearings 107. Suction tubes 115a are mounted on the cylinder. The tubes 115α rotate clockwise in FIG. 6 and in their lowest position they suck the loosened edge 85 of the uppermost one at the lower ends StofTstücks 82 ', which then hugs the profile of the pipe ends. One run on the cylinder 105 Number of rollers 109 over which conveyor belts 100 'are guided. These bands support the Stoffstückc, while the suction pipes 115 σ around rotate an axle 117; they then take the pieces of fabric from the suction tubes as they run off the rollers off and convey them for further processing after 118. To ensure that the top is of the stack is at the correct height with respect to the rotating suction pipe, the position of the Nozzle 88 in the middle of a spring-operated microswitch 180 discharged, which controls the setting of the lifting device 87. This microswitch is on the lifting device 87 attaches and controls their drive via its contacts.

To be able to remove pieces of fabric or towels of different lengths from the stack and the removed ones Towels in close succession on the conveyor belts running at constant speed The vacuum tubes run to be able to transport 100 ' 115 a during part of its revolution at different speeds of rotation, see above that they whenever a piece of conveyor belts corresponds to the length of the particular stack has passed, are back in the lowest position to grab the next towel. The machine can therefore, for example, have a variable-speed drive 119 for the cylinder 105 and a slip clutch 121 included, so that the cylinder 105 during one revolution either wholly or partially at a lower speed than the drive 119 when a Force on the cylinder can rotate. A parallel to the cylinder plate 124 can through the Pipes 115 ο gchaltcrl and in a larger radius be arranged as the periphery of the rollers 109.

When the α Saugrohrc 115 a piece of turn during which the bands do not lie on the rollers 109, the variable in the rotational speed of the drive mechanism 119 controls the speed of the Saugrohrc 115a. However, when the tubes 115 'reach the point at which the belts are back on the rollers, the belts press on the plate 124 and exert such a force that the coupling 121 slips and the suction tubes 115 o with one through. Running speed of the belts i00 run around a certain rotational speed until the belts 100 'are uncoupled from the rollers again. The speed of the drive 119 is adjusted according to the length of the pieces to be removed. It is sufficient if the cylinder 105 makes one revolution per towel length; when the tubes 115 'of rotation reach a point Y before they engage the towels, a rotating member 97 can actuate a valve 126 which causes air to be blown against the edge 85 of the towel so that a if necessary, the folded end of the towel is straightened again.

8 and 9, a lifting device is shown which has a blow nozzle plate 20 a, as in FIG. 2 b shown contains; it is arranged near the edge of the topmost piece of the stack and has I.uftdüscn 16 α of the type described above. However, the plate 20 a is provided with downwardly bent parts 20 h which press on the edge of the stack. A force-fit attacking device i40, e.g. B. a cylinder covered with shark skin engages the topmost piece along a line of action running between the air nozzles. The apparatus 140 pulls on the top piece of fabric da.s under the downward bent parts 20 b hindurchglcitct, while the underlying pieces remain perfectly aligned lying on the stack.

1 sheet of drawings 309 540/1

Γ, 7 «

Claims (5)

Patent claims: 1. Lifting device for permeable pieces of tissue or the like. From a stack by means of a Blow nozzle arrangement, characterized in that that above the stack (22) a nozzle plate (20) can be displaced against the effect of its own weight over the stack surface is supported, the effective area of the nozzle plate (20) being a substantial part of the Stack surface and the nozzle cross-section (16) occupies a substantial part of the area of the nozzle plate. 2. Lifting device according to claim 1, characterized in that the nozzle plate (20 "') is provided with flexible side parts (23). 3. Lifting device according to claim 1, characterized in that outer areas (20 b) of a rectangular blow nozzle plate (20 a) are arched downwards (F i g. 9). 4. Lifting device according to claim 1, characterized in that the outer regions (56) of a nozzle plate (50) curved upwards and backwards and provided with radial slots (68) are. 5. Lifting device according to one or more of the preceding claims, characterized in that the blowing nozzle plate (20, 20 a, 50) is followed by a further conveying device (140) in a manner known per se.