GB2079258A - Intermittently Feeding Fabric to Pivoted Scale Pan for Forwarding in a Tensionless State to a Cutter - Google Patents

Abstract

Fabric (A) is fed via feed rolls (2, 3) to pivoted scale pan (5) only whilst the pivoted arm (9) for the scale pan (5) is pivoted anticlockwise (as shown) with the transmission wheel (7) carried on the pivoted arm connecting the drive wheel (6) with feed rolls (2, 3). The pivoted arm (9) and the scale pan (5) are retained in the upper (i.e. pivoted anticlockwise) position by spring (12) rages acting on one end of the arm and the attraction between magnets (13, 19) carried on arm (9) and pivoted lever (14). As the drive wheel (6) rotates, it pivots lever (14) anticlockwise thereby causing the weight of fabric on scale pan (5) to pivot arm (9) on its lower (i.e. pivoted clockwise) position and disengaging transmission wheel (7) from drive wheel (6) to stop the fabric feed to the pan (5). Continued rotation of drive wheel (6) permits lever (14) and magnet (19) to pivot back to their original positions but the scale pan (5) pivots anticlockwise to its original position only after some fabric has been withdrawn from the scale pan in direction (B). The magnet (13) attached to the end of scale pan arm (9) then holds the scale pan (5) in its upper position during further delivery of fabric to the scale pan (5). The arrangement permits feeding of the fabric in direction (B) to a cutting machine in a tensionless state. <IMAGE>

Description

SPECIFICATION Feeding Device for Fabric in a Band Cutting Machine The present invention relates to a device for feeding fabric in an automatic band cutting machine to a cutting means for cutting the fabric into bands. The cutting means can consist of one or several cutting knives or cutting rollers.

In order to be able to cut the fabric in aimed equal bands in an automatic operating cutting machine it is of essential importance that the cutting means is all the time fed with tension-free fabric. Different kinds of feeding devices in order to solve this problem are previously known.

In one known construction for solving said problem the fabric is deposit folded, i.e. folded backwards and forwards, on a storage plate, from which the fabric is fed in a slack condition upwardly to the cutting means. Existing difficulties with this method is, however, that the fabric is stuck to its own fibers and that weight changes on the suspended part of the fabric occurs as the fabric is advanced and cut, which results in friction disturbances that influence the cutting result.

In other known constructions, the fabric is stored on a storage roll, which also is the most common method to store the fabric. In order to solve said problem it is known to use different types of swing bars having electric operation of different kinds. In one known such construction a swing bar is arranged such that the feed of the fabric is started twice each revolution when magnets pass transmitters positioned on the support column of the cutting machine. In another known such construction in order to meet the desire that the feed shall start independent of where the swing bar is, electric slip rings have instead been arranged. The disadvantage with these constructions is, however, that they are very expensive.

As distinguished from the above mentioned constructions the present invention provides the feeding device which combines simplicity and thereby cheap manufacture with high accuracy as to the cutting of the advanced fabric into bands.

The characteristics of the invention for obtaining this appear from the following claims.

One embodiment of a feeding device according to the invention is in the following described more in detail with reference to the enclosed drawing, which in side view schematically shows the feeding device.

On the drawing is for illustrating the invention only shown the feeding device and a portion of a storage roll, from which the fabric is advanced by means of the feeding device. Remaining parts of the band cutting machine can be whatever construction to which the feeding device according to the invention is adaptable. Moreover, the feeding device is as well fit for use, when the fabric instead of being stored on a roll is stored as folded fabric.

The storage roll has on the drawing the reference numeral 1 and the fabric advanced from the roll has the reference numeral A. The fabric is advanced by means of a feed roll 2 between this roll and a pressure roll 3 and is thereafter advanced via a wiper plate 4 to a scale 5.

A driving wheel 6 is during the feed of the fabric drivingly in contact with a transmission wheel 7, which preferably along its circumference consists of rubber material. The transmission wheel 7 in its turn is drivingly in contact with a wheel 8 fixed to the feed roll 2. For the sake of lucidity only a part of the wheels 6 and 8 are shown.

The transmission wheel 7 and the scale 5 are in an appropriate way fixed to one arm of a double-armed swinging arm 9, which is pivotally journalled about a center 10 between a position shown with continuous lines and a position shown with dashed lines. Thus, the transmission wheel 7 and the scale 5 follow in the swinging movement and, in a corresponding way as for the swinging arm 9, the positions for the transmission wheel and the scale are shown with continuous and dashed lines, respectively. The swinging to the position shown with dashed lines takes place against the action of a spring 12 arranged between the other arm of the swinging arm 9 and a lever 11 and the swinging of the scale downwardly is limited by the abutment of the lever against a stop 1 6. A magnetic 13 is positioned at the free end of the other arm of the swinging arm 9.

The feeding device also includes a second double armed swinging arm 14 pivotally journalled above an axis 1 5 between a position shown with continuous line, in which one arm of the swinging arm abuts a stop 22, and a position shown with dashed lines. The swinging to the position shown with dashed line takes place against the action of a spring 1 7 and the swinging is caused by the fact, that a roll 1 8 on the drive wheel 6 affects the free end of said one arm of the swinging arm 1 4 once each revolution. When the roll 1 8 leaves the engagement with the free end in the position shown with dashed lines, the swinging arm by action of the spring 1 7 returns to the position shown with continuous lines.A magnet 1 9 faced to the magnet 13 of the swinging arm 1 9 is fixed to the free end of the other arm of the swinging arm 14.

The tension in the spring 12 arranged between the swinging arm 9 and the lever 1 which is pivotally journalled about an axis 20, can be controlled by means of a control screw 21 in contact with the end face of the lever opposite to the end at which the spring 12 is fastened to the lever.

The feeding device as shown operates in the following way.

In the position shown with the continuous lines with the magnets 13 and 14 lying close to each other, the attractive force between them is so high that the transmission wheel 7 is kept pressed in contact with the driving wheel 6 and the wheel 8 fixed to the feed roll 2. The transmission wheel 7 transmits in this position the rotary motion of the driving wheel to the feed roll 2 and fabric is advanced from the storage roll 1 to the scale 5.

When the roll 18 on the drive wheel 6 during the rotation thereof affects the lever 14, the lever is swung against the action of the spring 1 7 to the position-shown with dashed lines, i.e. the magnet 1 9 is swung to its lower position shown with dashed lines, and such a big gap ensues that the attractive force between the magnets 1 3 and 1 9 ceases or at least is so small, that after adapted amount advanced fabric to the scale 5 the weight of this fabric and of the scale causes the scale to fail down to abutment of the swinging arm 9 against the stop 1 6 and against the action of the spring 12, i.e. to the lower position shown with dashed lines.Thus, the ewg g arm 9 is swung to the position shown with dashed lines meaning that the magnet 13 is raised to its upper position shown with dashed lines and t the transmission wheel 7 is disengaged from the driving wheel 6 and the wheel 8, whereby the driving of the feed roll and thereby the feed of the fabric ceases.

Each time the roll 1 8 during the rotation of the driving wheel 6 become disengaged from the free end of the swinging arm 14, the swinging arm returns to the position shown with continuous lines. The distance between the magnets 1 3 and 1 9 is, however, in this position still so large, that the magnet force between them is not able to draw the magnet 13 towards the magnet 1 9 and the scale remains in its lower position until so much fabric has been fed from the s'cale to the cutting means of the machine (arrow B), that the spring 12, is able to draw downwardly the arm of the swinging arm 9 provided with the magnet 13.

The magnet 13 then approaches the magnet 19 and a contraction to the position shown with continuous lines is obtained. By the magnets (and the spring 17) the transmission wheel 7 now comes to pressed abutment against the driving wheel 6 and the wheel 8 and a new feed of fabric is started and continues until the gravitational force of the scale 5 and the fabric fed to the scale exceeds the spring force of the spring 12 when the magnet 1 9 has swung down to its lower position. During the continuing driving of the feeding device the magnet 1 9 accordingly serves as a sensing means, which for each revolution of the driving wheel 6 senses the position for the magnet 1 3.

Essential for the simple structure and the reliable function of the shown feeding device according to the invention is accordingly the magnets 13, 19 and their guided movement as well as the spring 12. After an initial setting of the magnet, it is the spring 12 that decides how much the fabric fed to the scale 5 is allowed to weigh.

As mentioned above, the tension in the control spring 1 2 can by means of the control screw be affected in order to obtain an appropriate balancing of the scale 5 and the amount of fabric fed to the scale.

The feeding device in a band cutting machine as described above and shown on the drawing accordingly units simplicity in structure with high accuracy in the cutting work by the constantly guaranteed feed of tension-free fabric from the scale to the cutting means of the band-cutting machine. However, the invention is not limited to just this construction but can be varied in several ways within the frame of the following claims. For instance can instead of spring 1 2 an appropriately positioned counter-weight be arranged and the lever 14 can be affected by another influencing means than roll 18 and more than once each revolution for the driving wheel 6. Nor does the driving means with necessity need to be a driving wheel and the transmission consists of a wheel, even if this is preferred.

Claims (7)

Claims

1. A feeding device in a band cutting machine for feeding fabrics (A) from storage means (1) to cutting means for cutting the fabric into at least one band, including a feed roll (2) driven intermittently in feeding periods, characterized in scale means (5) positioned in the feed direction for the fabric (A) after the feed roll (2) and arranged for collecting fabric fed to said scale means during one feeding period, from which scale means the fabric in tension-free condition is fed to said cutting means and which is positioned in an upper or lower position depending on the weight of the fabric positioned on said scale means relative to a force (12) acting on said scale means, transmission means (7) drivingly in engagement with drive means (6) and said feed roll (2) in one of said positions for said scale means (5) for feeding the fabric during the feeding period and out of engagement with said drive means and said feed roll in the other of said positions of said scale means, and magnets (13, 19) forced movable towards and from each other, said magnets in said one position for said scale means (5) being positioned adjacent to each other and holding said transmission means (7) in said driving engagement and in said other position for said scale means being positioned at a iarger distance from each other.

2. A feeding device according to claim 1, characterized in that said scale means (5), said transmission means (7) and one (13) of said magnets are mechanically connected to each other and that the other (19) of the magnets is by said drive means (6) influenced for movement towards and from said one magnet (13) during regularly recurrent time periods.

3. A feeding device according to claim 2, characterized in that said scale means (5), said transmission means (7) and said one magnet (13) are arranged at a swinging arm (9), said scale means being arranged at one end of the swinging arm and said magnet (13) being arranged at its opposite end.

4. A feeding device according to claim 2 or 3, characterized in that said other magnet(19) nged at one end of a second swinging arm (14), the opposite end of which is arranged to be influenced by said drive means (6).

5. A feeding device according to claim 1, characterized in that said drive means (6) consists of a driving wheel and that said transmission means (7) consists of a wheel.

6. A feeding device according to claim 1, characterized in that said force is obtained from a spring (12) adjustable as to its tension.

7. A feeding device in a band cutting machine substantially as hereinbefore described with reference to the accompanying drawing.