Apparatus and method for piercing cloth

Abstract

 A circular hole (5) can be pierced by bringing a circular edge (4) of a cylindrical rotary piercing punch (3) into rotation-contact with a ground fabric (2) placed on the ground fabric base (1), the ground fabric base (1) comprising a filament bundle (7) densely housed in a container (8) or in a recess provided on a plate (1a), thus providing a rough upper surface to the base (1). A clearly-defined hole (5) with a sharp periphery can thus be pierced in the ground fabric (2) by means of the edge (4) while pressing the ground fabric (2) onto the rough surface of the base (1) by means of the edge (4) which also serves to keep the fabric (2) stationary. The ground fabric base (1) may be hardened by causing an adhesive (9) to penetrate into the upper portion of the filament bundle (7).

Description

[0001] The present invention relates to a cloth piercing apparatus based on a rotary punch, a ground fabric base in said piercing apparatus and a cloth piercing method suitably applicable when piercing a hole in a ground fabric of a woven or non-woven fabric or leather.

[0002] As an apparatus for forming a hole pattern in a cloth, there has been available, for example, that disclosed in Japanese Unexamined Patent Publication No. 08-158235.

[0003] The referred conventional art relates to a hole pattern sewing apparatus wherein a needle bar in an automatic stitching machine is made freely stoppable and operable during operation of the machine; there is provided a rotary knife which forms a hole in a ground fabric, driven by driving means attached to a rotary knife stand descending during stoppage of the needle bar; there is further provided a needle guide guiding a needle at the lower end of the needle bar at the lower end of a lifting bar provided adjacent to the needle bar; and there is provided interlocking means which causes the lifting bar to go down to the lower end to guide the needle only when forming a seam in a hole formed in the ground fabric by means of the rotary knife.

[0004] In this apparatus, more specifically, upon stoppage of the needle bar at the upper limit in response to a specific signal during operation of the automatic stitching machine, the rotary knife stand goes down to cause the rotary knife having a sharp tip penetrates into the ground fabric while rotating; the rotary knife thus reams the ground fabric to form a hole having a fluffy periphery, and then the rotary knife stand goes up. Then, a stitching frame moves. The just formed hole displaces to immediately below the needle bar. Then, the needle guide goes down at a slightly earlier timing than the needle to ream the hole to a prescribed size and holds the same in this state.

[0005] Thereafter, the needle goes down into the needle guide having penetrated into the hole as described above, forms a seam, and goes up. When the needle goes up and the needle guide as well goes up, the stitching frame moves and the portion of the ground fabric not containing the hole displaces to directly below the needle bar and stops there. Then, the needle moves up and down to form a seam on the portion not containing the hole.

[0006] Further, when the needle having formed the seams goes up and leaves the ground fabric, the stitching frame moves again to cause the portion of the ground fabric having the hole to displace to directly below the needle. In the same manner as in the preceding run, the needle guide and the needle go down to form another seam. When the needle and the needle guide go up, the stitching frame moves. Seams are formed around the hole made in the ground fabric through repetition of the aforesaid operation.

[0007] The rotary piercing drill called the rotary knife in the conventional art described above has a circular-cone-shaped or pyramid-shaped sharp tip at the lower end, and tapered blades are provided at four positions along the cone portion as in a glass pen of old days: "These blades shall not have an edge so as not cloth" as is described in column "0018" of the publication of the foregoing conventional art which is the only embodiment of the conventional case.

[0008] In order to pierce a hole in a cloth by means of such a rotary knife having a sharp tip, a cone-shaped rotary knife is driven into a ground fabric having nothing in contact with the lower surface thereof while rotating the rotary knife, and then the ground fabric is reamed while scratching off the ground fabric with rotary blades, thereby piercing a hole, as described above.

[0009] Because this hole has a fluffy peripheral surface, therefore, it is necessary to clearly identify the hole periphery by "looping" the fluffy portion while spreading this portion. The first problem in the conventional art is therefore a complicated and troublesome operation.

[0010] Further, in order to accomplish the aforesaid "looping" with a serving machine needle in the conventional art, it is necessary to do it while pressing fluffy to outside with a "needle guide" provided around the needle, as described above, and this poses the second problem of a complicated operation, and in addition, there is posed another problem of difficulty in piercing a large hole of over 5 mm in the cloth.

[0011] Apart from the foregoing conventional example, there is available a large-sized large-area fabric base as a base for placing a cloth for cutting with a lifting knife blade into a roughly shaped wide long outline, formed by preparing a rectangular block of about 900 cm² formed from many flexible plastic fine pieces having a diameter within a range of from 1 to 3 mm and a height of about 10 cm arrange at prescribed intervals in the shape of a rough hair brush, and many of such blocks are arranged in parallel. This conventional tool is to obtain a product by sucking air from below the cloth, cutting the cloth into a desired pattern by means of a lifting knife edge from outside onto the cloth pressure-positioned under an air pressure on the aforesaid fabric base, and then causing the lifting knife edge to swing out the cloth.

[0012] In the conventional case, therefore, the fine plastic piece is seriously deformed by the external force. This poses an essential problem in that even if an outline can be punched through the cloth by means of a flat-edge cutter, it is impossible to beautifully punch a closed circular hole from the cloth with a rotary punch.

[0013] Further, a hole can be pierced in a thick sheet of paper or a cloth with a circular edge of a rotary hollow pipe. Since the base for the paper or the cloth is simply made of plastics or wood, however, there is posed a problem in that only a few runs of piercing make the surface irregular, thus making it impossible to pierce a clear hole in the cloth.

[0014] The present invention has an object, when piercing a circular hole with a circular edge of a cylindrical rotary punch in a ground fabric such as a woven or non-woven fabric or leather, with a view to eliminating the foregoing problems, to permit easy and rapid piercing of beautiful hole having a clear periphery and free from fluff only by placing a desired ground fabric on a fabric base having an upper surface of a special structure or a fabric base having a rough surface or a frictional surface, and to extend the service of the foregoing ground fabric base.

[0015] Another object of the present invention is to permit easy and rapid piercing of a beautiful hole having a clear periphery and free from fluff by method of piercing a hole by placing a desired ground fabric on the fabric base having such a special structure.

[0016] The foregoing objects of the invention can be achieved by using a piercing apparatus for cloth based on a rotary punch, for piercing a circular hole by bringing a circular edge of a cylindrical rotary piercing punch into rotation-contact with a ground fabric placed on the ground fabric base, wherein the ground fabric base comprises a filament bundle made by bundling a plurality of flexible plastic filaments densely housed in a container, and having the upper portion of the filament bundle hardened by causing an adhesive to permeate therein.

[0017] The foregoing objects of the invention can be achieved also by using a piercing apparatus for cloth based on a rotary punch, wherein the filament bundle is prepared by inserting a plurality of flexible filaments comprising long plastic filaments into a slightly larger-sized heat-shrinkable tube t, tightly bundling the flexible filaments by causing the tube t to heat-shrink to form a long filament bundle, and cutting the long filament bundle into a desired length.

[0018] The foregoing objects of the invention can be achieved also by using a method of piercing a hole in a cloth with a rotary punch using the foregoing ground fabric base.

[0019] The foregoing objects of the invention can be achieved also by using a round fabric base in a piercing apparatus for cloth based on a rotary punch used in said apparatus for piercing a circular hole by bringing a circular edge of a cylindrical rotary piercing punch into rotation-contact with a ground fabric placed on a ground fabric base, wherein the ground fabric base comprises a filament bundle made by bundling a plurality of flexible plastic or metal filaments a multiple-fiber rigid body or rigid needles densely and fixedly arranged on a plate, thereby forming the ground fabric base having a rough or frictional upper surface.

[0020] As a ground fabric base having a rough upper surface, a filament bundle formed by bundling a plurality of the aforesaid flexible filaments, bamboo spits or tooth pick-shaped fine bamboo rods, or a multiple-fiber rigid body may be used by cutting the same to a desired length by placing the same into a semi-circular groove in a lower die and bringing down a edge plate of a upper die.

[0021] A the aforesaid multiple-fiber rigid body, a collection of fine bamboo pieces may be employed.

[0022] Further, as a ground fabric base, one formed by using a plurality of rigid needles with the tip thereof directed upward and densely and fixedly arranging the plurality of rigid needles in a container or in a recess in the base may be employed. Or, it is also possible to use the aforesaid filament bundle formed by bundling the plurality of flexible filaments, or the multiple-fiber rigid body or the rigid needles by casting an adhesive into gaps in the upper portion thereof, and causing penetration, drying and solidification. Instead, the ground fabric base may be used by causing an adhesive to permeate into the upper portion of the filament bundle or the like arranged in the ground fabric base and hardening the same.

[0023] A base having a frictional upper surface may also be formed, as the aforesaid base, by arranging and fixing semi-hard synthetic resin member or semi-hard synthetic rubber pillars at prescribed position of a plate.

[0024] The aforesaid filament bundle may be prepared by inserting a plurality of flexible filaments comprising long plastic filaments into a slightly larger-sized heat-shrinkable tube, tightly bundling the flexible filament by causing the tube to heat-shrink to form a long filament bundle, and cutting the long filament bundle into a desired length.
By way of example only, embodiments of the invention will now be described in greater detail with reference to the accompanying drawings of which:

Fig. 1 is a perspective view illustrating an example of configuration for the application of the present invention;

Fig. 2 is a longitudinal sectional view illustrating an example of configuration for the application of the invention;

Fig. 3 is a perspective view illustrating an example of manufacture of a filament bundle used in the invention;

Fig. 4 is a longitudinal sectional view illustrating the state of elevation of the rotary punch 3 shown in Fig. 2;

Fig. 5 is longitudinal sectional view illustrating another example of configuration for the application of the invention;

Fig. 6 is a longitudinal sectional view illustrating the sate of elevation of the rotary punch shown in Fig. 5;

Fig. 7 is a longitudinal sectional view illustrating a case where a filament bundle is arranged on, and fixed to, a plate in the invention;

Fig. 8 is a perspective view illustrating an example of manufacture of a multiple-fiber rigid body in the invention;

Fig. 9 is a perspective view illustrating an example of installation of fine bamboo pieces in the invention;

Fig. 10 is a longitudinal sectional view illustrating an example of installation of rigid needles in the invention; and

Fig. 11 is a longitudinal sectional view illustrating another example of the ground fabric base in the invention.

[0025] First, the principle of the invention comprises, as shown in Figs. 1 and 2, the steps of placing a ground fabric 2 such as a woven cloth to be pierced on a ground fabric base fixed at a desired position of a plate la such as a known ditch board made of a metal or the like of, for example, a stitching machine, and bringing a circular edge 4 of a cylindrical piercing punch 3 chucked to a known rotary piercing tool 3A such as a pneumatic rotary blade type or the like into rotation-contact with the ground fabric 2 as shown in Fig. 2, thereby piercing a circular hole 5 having a diameter within a range of from 1.5 to 10 mm in the ground fabric.

[0026] In the invention, the foregoing ground fabric base 1 is prepared by bundling a number of flexible filaments 6 as shown in Fig. 3(a) comprising filaments made of plastics such as nylon or polypropylene and having a diameter within a range of from 0.3 to 1.0 mm, cutting the same to a desired length, and densely housing the resultant filament bundle 7 as shown in Fig. 3(e) in a metal or plastic deep-dish-shaped container 8.

[0027] Or, the foregoing ground fabric base may be prepared by bundling a number of flexible filaments 6 as shown in Fig. 3(a) comprising fine metal curled filaments made of fine metal lines for a rust removing brush using stainless steel or brass lines and having a diameter within a range of from about 0.1 to 0.5 mm, cutting the same to a desired length, and densely and fixedly arranging longitudinally the resultant filament bundle as shown in Fig. 3(e) in a metal or plastic deep-dish-shaped container 8, thereby forming a ground fabric base 1 having a rough upper surface.

[0028] Then, an adhesive 9 such as that for preventing yarn entanglement is caused to penetrate into fine gaps between filaments in the upper portion of the foregoing filament bundle 7 under the effect of capillary action and hardened. On the resultant ground fabric base 1, the rotary punch 3 having descended as shown in Fig. 2 reams a desired portion of the filament bundle 7 in a densely bundled state via the ground fabric, or the hardened filament bundle 7 as described above, thus permitting piercing of a circular hole 5 as shown in Figs. 2, 5, 10 and 11 in the ground fabric 2.

[0029] Upon piercing, when the filament bundle 7 has a rough upper surface, a transverse shift of the ground fabric can be prevented upon pressing the edge 4 of the rotary punch 3 onto the ground fabric 2, thus making it possible to pierce a beautiful circular hole 5 in the ground fabric 2.

[0030] After piercing, the filament bundle 7 in the container 8 restores the original dense housed state shown in Figs. 4 and 6 under the effect of intrinsic elastic force of the material by causing the rotary punch 3 to go up as shown in Fig. 4 and 6.

[0031] The filament bundle 7 can be housed in the container 8 by arranging the plurality of flexible filaments 6 cut to a desired length in parallel with each other in the longitudinal direction in the container 8.

[0032] In place of the container 8, a recess integrally drawn or formed in a plate la such as a ditch board at a desired position may be used.

[0033] Further, the foregoing filament bundle 7 may be prepared by inserting a plurality of flexible filaments 6 comprising long metal filaments or plastic filaments as shown in Fig. 3(a) into a slightly larger-sized heat-shrinkable tube t, tightly bundling the flexible filaments 6 by causing the tube t to heat-shrink as shown in Fig. 3(c) to form a long filament bundle 7a, and cutting the long filament bundle 7a into a desired length by means of a knife blade 11 by placing the long filament bundle 7a in a semi-circular groove 10a in a lower die as shown in Fig. 3(d) and causing the knife blade 11 of the upper die to go down. The resultant filament bundle 7 as shown in Fig. 3(e) may be employed.

[0034] The components represented by symbol S in Figs. 1, 2,4, 5 and 6 are springs for holding the ground fabric, suspended around the rotary punch 3. When the ground fabric 2 is secured by a separate frame, the springs S may be omitted, and a circular hole 5 can be pierced in the ground fabric 2 with no problem.

[0035] In Fig. 1, P represents a flexible pipe for injecting an air flow from an air source such as a known compressor separately provided onto a known windmill type rotary blade provided in the piercing tool 3A. An air jet type rotary piercing tool 3A which rotates at a speed of from 100 to 500 revolutions per second, driven by the rotational force of the aforesaid rotary blade in the invention. This rotary piercing tool may be a known electrically driven rotary piercing tool such as a compact high-speed electric drill.

[0036] A ground fabric base 1 having a rough upper surface as shown in Fig. 8 may be prepared by placing a multiple-fiber rigid body 6A comprising a plurality of fine hard wooden bars bundled together in a semi-circular groove 10a of a lower die 10, and causing a knife blade 11 of an upper die to go down to cut the same to a desired length.

[0037] The multiple-fiber rigid body made by bundling the plurality of fine hard wooden bars may comprise fine bamboo rods such as bamboo spits or toothpick-shape ones having a diameter of from about 0.5 to 2 mm.

[0038] In place of the multiple-fiber rigid body made by bundling the plurality of fine hard wooden bars as described above, fine bamboo pieces 6B made by dividing a relatively thick bamboo into pieces of about 3 mm³ may be collected in a number of from 5 to 10 with the upper surfaces aligned as shown in Fig. 9.

[0039] When using a multiple-fiber rigid body or the like, therefore, it suffices to be capable of being arranged in, or fixed to, the container 8 of the ground fabric base 1 or the recess in the base: for example, a plurality of fine rods are to be bundled, or in the case of wide bar-shaped pieces, the number of pieces in the bundle should correspond to the size of the container 8 or the recess in the base. For example, a single multiple-fiber rigid body may be arranged and fixed longitudinally along the fiber direction.

[0040] The ground fabric base 1 may comprise a plurality of rigid needles 6C having a diameter of from 0.3 to 0.7 mm densely and fixedly arranged in a container 8 or in a recess in the base with the tips thereof directed upward as shown in Fig. 10, thereby forming a ground fabric base 1 having a rough upper surface, or the plurality of rigid needles 6C may be hardened by causing an adhesive 9 to penetrate into gaps in the upper portions thereof as shown in Fig. 10.

[0041] A ground fabric base 1 having a frictional upper surface may be prepared by preparing a semi-hard synthetic resin member 6D having a hardness to an extent that strong pressing with a surface of a cube having a volume of about 1 cm³ such as a small driver tool by a male adult operator produces a slight recess, and arranging the thus prepared semi-hard synthetic resin member 6D in a container 8 of a plate la and fixing the same thereto as shown in Fig. 11, and the semi-hard synthetic resin member 6D may be made of a semi-hard synthetic rubber pillar made of hard neoprene or polyurethane.

[0042] In these cases, a beautiful small hole having a clear outline can be pierced in the ground fabric 2 with the rotary disk edge 4 while pressing the ground fabric 2 on the base 1 with the rotary circular edge 4 of the rotary punch 3 against the frictional upper surface of the base to keep the same stationary.

[0043] Ascent and descent of the foregoing rotary piercing tool 3A may be accomplished by manually operating the piercing tool 3. This operation may be conducted also by the use of a known compact drilling machine from among general machine tools. A beautiful hole could instantaneously be pierced in the ground fabric 2 on the base 1 fixed to a plate la such as a ditch board of a sewing machine as shown in Figs. 1 and 2, by causing ascent and descent in the same manner as handling of the needle through the steps of removing the needle and the cloth pressor from a multi-hard type stitching machine head and setting the foregoing long and slender rotary piercing tool 3A with the use of a

-shaped fitting.

[0044] In this case, it is possible to stop a bray by "looping" the periphery of the circular hole 5 pierced in the ground fabric 2 with the needle of second adjacent needle bar while keeping the rotary piercing tool 3A lifted by the first needle bar at the elevated position after piercing the hole in the ground fabric 2, and at the same time, to form a wide-ring-shaped stitching pattern around the circular hole 5.

[0045] The filament bundle 7 maybe house from above as shown in Fig. 7 (b) in the container 8 on the bottom of which the adhesive 9 has previously poured as shown in Fig. 7(a), and a ground fabric base 1 used in the invention as shown in Figs. 7(c) and 11 may be formed by bonding the lower portion of the filament bundle 7 to the bottom in the container 8.

[0046] In this case, even when a slightly lower degree of density of the filament bundle 7 or a slightly smaller semi-hard synthetic rubber member 6D, it is possible to prevent the filament bundle 7 or the rubber member 6D from coming off the container 8.

[0047] By providing a side groove 3a on the side closer to the circular edge 4 of the rotary punch 3 as shown in Figs. 5, 6, 10 and 11 to bring the rotary punch 3 down, it is possible to pierce a circular hole 5 in the ground fabric 2, the rotary punch 3 reams the desired portion of the filament bundle 7 in a densely bundled state or the hardened filament bundle 7 via the ground fabric 2. At this point, flocks and hards 2a accumulating in the rotary punch 3 as shown in Figs. 5, 6, 10 and 11 can be removed from the side groove 3a closer to the circular edge 4 of the rotary punch 3.

[0048] Further, when an outer sleeve 8A of the container 8 is attached, via racing receptor 8B represented by a one-point chain line in Figs. 4 and 6 relative to the ditch board la so as to permit rotation of the container 8 with only a slight force, it is possible, when piercing a plurality of beautiful holes in the ground fabric 2, to considerably reduce the frequency of replacement of the filament bundle 7 and to provide convenience by dividing the piercing positions on the base 1 into a plurality of points through setting the piercing position at an eccentric point relative to the base 1.

[0049] When fine flocks and hards depositing on the rough surface of the filament bundle 7, the multiple-fiber rigid body 6A or the rigid needle 6C impairs cutting performance of the rotary punch 3, the initial state can be restored by removing such flocks and hards with a metal brush, causing an adhesive 9 again to penetrate in the upper portion of the filament bundle 7 of the like and hardening the same.

[0050] Because the foregoing configuration is adopted in the present invention, these are available the following advantages.

[0051] The first advantage is that, when piercing a circular hole 5 by bringing a circular edge 4 of a cylindrical rotary piercing punch 3 into rotation-contact with a ground fabric 2 placed on the ground fabric base 1, the ground fabric base 1 comprises a filament bundle 7 comprising a plurality of flexible filaments 6 such as plastic or metal filaments, a multiple-fiber rigid body 6A or rigid needles 5C densely housed in a container 8 or a recess provided on a plate la, thus forming a ground fabric base 1 having a rough upper surface, and a beautiful circular hole 5 with a clear periphery can be pierced in the ground fabric 2 by means of this edge 4 while pressing the ground fabric 2 onto the rough surface by means of the circular edge 4 of the rotary punch to keep the same stationary.

[0052] The second advantage is the possibility of extending the service life of the ground fabric base 1 by reinforcing the filament bundle 7 densely housed in the container 8 or in the recess of the plate, the multiple-fiber rigid body 6A or the rigid needles 68 through penetration of an adhesive into the upper portion and hardening thereof.

[0053] Furthermore, the foregoing filament bundle 7 or the multiple-fiber rigid body 6A can be prepared by inserting a plurality of flexible filaments 6 or fine bamboo rods comprising long plastic or metal filaments into a slightly larger-sized heat-shrinkable tube t, tightly bundling the flexible filaments 6 or the like by causing the tube t to heat-shrink, and cutting the same to a desired length, thereby obtaining the filament bundle 7 or the multiple-fiber rigid body 6A. This makes it easier to house the filament bundle 7 or the multiple-fiber rigid body 6A into the container 8, and there is available an additional advantage of easy and rapid manufacture of the filament bundle 7 or the multiple-fiber rigid body 6A.

[0054] Other advantages are inexpensive implementation and a simple configuration.

Claims

1. Apparatus for piercing a circular hole (5) in a ground fabric (2) comprising a rotary punch (3) having a circular cutting edge (4) and a base (1) onto which the ground fabric (2) to be pierced is placed, characterised in that the base (1) comprises a bundle (7) of parallel filaments (6) densely packed in a container (8) to provide a rough upper surface to the base (1).

2. Apparatus as claimed in claim 1 in which the bundle (7) of filaments (6) is prepared by inserting a plurality of flexible filaments into an over-sized, heat shrinkable tube, causing said tube to heat shrink around said filaments (6) to form a long bundle (7a), and cutting the bundle (7a) to a desired length.

3. Apparatus as claimed in claim 1 in which the bundle of filaments comprises a plurality of flexible metal filaments (6) fixedly arranged on a plate (1a).

4. Apparatus as claimed in claim 1 or claim 2 in which the bundle of filaments comprises a plurality of fine bamboo rods.

5. Apparatus as claimed in claim 1 or claim 2 in which the bundle of filaments comprises a plurality of rigid needles (6c) fixedly arranged on a plate (1a) with the tips thereof directed upwards.

6. Apparatus as claimed in any one of claims 1 to 5 in which the upper portion of the bundle (7) of filaments (6) is hardened by means of an adhesive (9) permeated therein.

7. Apparatus for piercing a circular hole (5) in a ground fabric (2) comprising a rotary punch (3) having a circular cutting edge (4) and a base (1) onto which the ground fabric (2) to be pierced is placed, characterised in that the base (1) comprises a semi-rigid synthetic resin member (6D) arranged on, and fixed to, a plate (1a) and presenting an upper surface for frictional engagement with the ground fabric (2).

8. Apparatus as claimed in claim 7 in which the resin member comprises a semi-rigid synthetic rubber pillar.

9. A method of piercing a circular hole (5) in a ground fabric (2) using a rotary punch (3) having a circular cutting edge (4) and a base (1) onto which the ground fabric (2) is to be placed characterised by the steps of packing a bundle (7) of filaments (6) densely into a container (8) to form said base (1), and causing an adhesive (9) to permeate into the filament bundle (7) to harden the upper portion thereof.

10. A method as claimed in claim 9 in which the bundle (7) of filaments (6) is prepared by inserting a plurality of flexible filaments (6) into an over-sized, heat-shrinkable tube (t), causing said tube (t) to heat shrink around said filaments (6) to form a long bundle (7a), and cutting the bundle (7a) to a desired length.

Drawing