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(11) | EP 0 159 124 B1 |
| (12) | EUROPEAN PATENT SPECIFICATION |
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| (54) |
A pile wire blade holder and blade Klingenhalter und Klinge für Florgewebe Porte-lame et lame pour des tissus à poil |
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| Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention). |
[0001] The present invention is concerned with a pile wire assembly for use in looms for weaving cut pile fabrics.
[0002] In known pile wire assemblies, a blade is located at one end of the pile wire and includes a cutting edge inclined upwardly towards that end of the pile wire. As the pile wire is passed in one direction across the loom through loops formed by the wire the cutting surface of the blade slices through the warp yarn loops located above the pile wire to produce the cut pile fabric. The pile wire is constantly moved backwards and forwards across the loom at high speed and accordingly the pile wire is continually being subjected to vicious acceleration and deceleration which in turn causes the blade to exert to-and-fro forces in the blade holder during operation. Wear tends to occur in the blades and holders due to fretting, impact and friction.
[0003] In moquette or epengle applications, with very low pile wires and fine pitch, the size of the pile wire is severely limited and this can cause the pile wire to flex under the acceleration and deceleration and other forces encountered in weaving.
[0004] U.K. Patent Specification No. 501 067 discloses a pile wire assembly comprising a pile wire which is formed with a longitudinal slot at one end thereof; a blade holder disposed at said one end of the pile wire and having an opening to receive a blade, which opening communicates with said slot formed in the pile wire; a blade which is located in said holder and extends along the pile wire with a base portion of the blade located in said slot, the blade having a tip portion at an end of the blade furthest from the blade holder; and an abutment which extends over a portion of said slot above said tip portion of the blade so as to prevent said tip portion coming out of engagement with said slot.
[0005] In this prior proposal, the blade is restrained from moving in one direction beyond the end of the pile wire, under rapid acceleration and cutting forces by engagement with an end wall of the blade holder. The aforesaid abutment defines a socket portion in the pile wire. Engagement of the tip of the blade with the socket over an extremely small area restrains the blade from moving along the pile wire in the opposite direction, under inertia forces, and also restrains the tip of the blade from rising up above the pile wire. The rising up of the tip of the blade could ruin a fabric, as the cutting action is impaired or terminated by complete loss of the blade from the blade holder.
[0006] Obviously, the blade has to be made of extremely hard metal because of the tough cutting job which it has to perform. However, it has been found that the hard blade tends to wear away the blade holder around its small contact areas and ultimately cuts through the top or bottom of the socket with ruinous results to the fabric. If a fabric is not to be so ruined then the pile wires have a limited life and must be replaced before the wear of the socket has progressed too far. It will be appreciated that the wire holder gradually becomes worn and the fit of successive replacement blades becomes more slack thus resulting in even more rapid wear.
[0007] In a previously proposed pile wire assembly, a blade is inserted by first locating the tip of the blade in a closed, angled socket and then pivoting the blade downwards about the socket. Engagement of the tip of the blade with the socket prevents the blade moving relative to the wire in one direction, but again, because of the relatively small area of contact between the tip and the socket, the latter soon becomes worn with the consequence that the tip of the blade can rise above the wire resulting in the ruination of the fabric as previously referred to. Furthermore, where a dead end socket is provided, the socket can become clogged with dirt so that the top of a new blade cannot be correctly located within the socket.
[0008] According to the present invention, there is provided a pile wire assembly comprising:
a pile wire which is formed with a longitudinal slot at one end thereof;
a blade holder disposed at said one end of the pile wire and having an opening to receive a blade, which opening communicates with said slot formed in the pile wire;
a blade which is located in said holder and extends along the pile wire with a base portion of the blade located in said slot, the blade having a tip portion at an end of the blade furthest from the blade holder; and
an abutment which extends over a portion of said slot above said tip portion of the blade so as to prevent said tip portion coming out of engagement with said slot:
characterised in that the blade holder and the blade are provided with respective parts which interengage to inhibit movement of the blade longitudinally in said slot in both directions along the slot.
[0009] The blade may be held within such a holder with the forces tending to move the blade in both directions along the wire being transferred between said interengaging parts, rather than the tip and the wire. Thus, the area of contact between the blade and the blade holder may be greatly increased from the corresponding area of contact between blade and pile wire in previous arrangements for example, the area can be increased by between fifteen and twenty times that previously used, with the result that the life of the blade holder may be greatly increased. As the forces which are tending to move the blade along the holder in both directions are transferred by contact between the components at a region other than the tip of the blade, the sharp tip of the blade does not tend to erode itself, and also does not tend to wear away the actual wire and abutment themselves. Thus a uniform and repeatable location may be provided for the blade by the blade holder. Furthermore, the blade holder may be accurate, reliable and ultra lightweight.
[0010] The blade holder and wire may be milled in order to provide said opening, the respective said part on the blade holder, and said slot. Such milling may permit the assembly to have a compact and firm form.
[0011] Preferably, the blade holder has a first side adjacent the pile wire and a second side opposite said first side, the blade is introduced into the blade holder by sliding the blade into said opening from said second side, and the blade is removed from the blade holder by sliding the blade out of said opening towards said second side. Thus, pivotal movement about the blade tip portion, with its consequential adverse forces, can be avoided.
[0012] The said interengaging parts may comprise a projection provided on the blade holder and a hole which is provided in the blade and receives said projection.
[0014] The blade holder and the blade may be provided with respective portions which interengage to inhibit pivotal movement of the blade relative to the blade holder and thereby inhibit movement of the blade in a direction which would tend to move the tip portion of the blade away from the wire. Thus, contact between the tip portion of the blade and the abutment in order to prevent or limit movement of the blade away from the wire may be reduced or avoided to decrease the wear which occurs on the tip portion of the blade or on the abutment. The aforesaid projection and hole may serve also as said respective portions which interengage to inhibit pivotal movement of the blade relative to the blade holder.
[0015] The abutment on the wire may be particularly useful where the wire is of small diameter, as the wire may tend to flex during use, especially during cutting, and the abutment can prevent this flexure from allowing the tip of the blade to be exposed.
[0016] Preferably, the blade has a natural flexure under which it is biassed in the blade holder into a position in which said respective parts interengage.
[0017] Said opening on the blade holder is preferably open at two opposite side faces of the blade holder such that two opposite lateral faces of the blade are visible and accessible when the blade is positioned in the blade holder.
[0018] The invention may be carried into practice in various ways, and some embodiments thereof will now be described, by way of example, and with reference to the accompanying drawings, in which:
Figure 1 is a perspective view of a first embodiment of a pile wire assembly including a blade holder and a blade, showing a portion of the holder including the region thereof arranged to receive the blade;
Figure 2 is a section through lines II-II of Figure 1 showing a blade mounted on the holder, and
Figure 3 is a perspective view similar to Figure 1 of a further embodiment.
As shown in Figure 1, a pile wire assembly includes a blade holder 10 arranged to receive and locate a blade 20 on the holder, and a wire 12 (only a part of which is shown) extending from the blade holder 10.
[0019] The blade holder 10 includes a recess, for example a recess 14 which is milled to provide a circular stud 16 of approximately 2 mm diameter projecting from the centre of the recess. Alternatively the recess may be coined in order to form the stud. In an alternative arrangement (not shown) the stud 16 may be located further forwards, on the edge of the recess to lessen the chance of dirt becoming trapped between the blade and the recess. As shown in Figure 2, the stud 16 is arranged to extend through a hole 18 in the blade 20. The blade 20 is arranged to extend through a milled opening 22 at the end of the holding portion, and within a slot 24 running along the wire 12. The tip of the blade is arranged to be wholly located within the slot under a bridge 26 located towards the end of the slot.
[0020] In use, the pile wire assembly moves across the loom, forwards on insertion and backwards on withdrawal or cutting stroke, with approximately three insertions per minute, depending upon the number of wires in the set (usually around 20). Each withdrawal and insertion (i.e. two movements of the wire and therefore four attempted inertia movements of the blade within the holder) takes only 0.25 to 1.2 seconds, depending on loom width and speed, and speeds in the industry are generally increasing. Accordingly, at the beginning and end of each movement the momentum of the blade tends to attempt to move the blade in one direction or the other along the holder. Similarly the tip of the blade will tend to move up and down relative to the slot. Additional movement of flexure of the wire also tends to occur, particularly where the wire is extremely thin, for instance in moquette or epengle production the wire which governs the loop size may be as small as 1 mm in diameter, and rarely above 2.7 x 1.2 mm rectangular section.
[0021] All forces tending to cause the blade to move relative to the rest of the assembly are transferred at the blade holder 10. The stud 16 engages with the matching hole 18 in the blade over a substantial area to inhibit movement of the blade along either direction of the blade holder. The stud 16 also prevents that portion of the blade from moving up or down. In one embodiment (not shown) pivotal movement of the blade about the stud towards the wire is prevented by the bottom of the blade abutting the base 28 of the holding portion and the bottom of the slot 24; pivotal movement in the opposite direction is prevented or limited by abutment of the top of the blade with the top surface 30 of the opening. In the illustrated embodiment, the holder includes a pair of parallel guides 36 which are accurately located above and below the stud in order to prevent or severely restrict pivotal movement of the blade about the stud. Accordingly, it can be seen that there is a considerable area of contact between the blade and the holder in order to resist movement of the blade relative to the holder in all directions, and thus wear between the two is dramatically reduced giving the blade holder a longer life.
[0022] Should the wire tend to flex downwardly in its traverse across the loom then the bridge 26 will engage with the tip 34 of the blade to prevent it from appearing above the slot 24.
[0023] In order to insert a blade into the holder, the tip of the blade is pushed in from the end of the holder into and through the milled opening 22 until the hole 18 passes over the stud 16 and the blade clicks into the position shown in Figure 2, under its natural flexure. In that position, the end of the blade which fits over the stud is held out of alignment with the extent of the slot 24 in order that the side 38 of the blade is pressed against the recess 14 surrounding the stud. The biasing of the blade against the recess serves to hold the blade more firmly and help prevent dirt from becoming trapped between the blade and the recess. If desired the recess can be inclined (as shown) away from the direction in which the slot extends in order that the blade can contact the complete area of the recess. In order to be able to remove the blade, the portion of the blade holder between the stud 16 and the opening 22 is completely open so that the hole 18 can be pushed off the stud and the blade slid rearwardly. To allow the blade to be deflected and moved rearwardly in order to remove the blade, an additional hole 32 is provided in the blade.
[0024] The angle of the cutting blade relative to the extent of the wire may be of any angle suitable for various cutting conditions. For instance, for man- made fibre applications, the angle is generally between 5° and 20°.
[0025] In an alternative embodiment (not shown) the side walls of the opening 22 are extendible at a height in excess of the body of the wire along the wire so that only a small amount of the blade projects above the wire at the cutting point thus giving further support to the blade in the direction transverse to the wire, this being especially important on very fine wires where strength is limited.
[0026] In Figure 3, like parts to those shown in Figure 1 have been given the same reference numeral. The difference between the embodiment shown in Figure 3 and that of Figure 1 lies in the shape of the stud and the corresponding opening in the blade. In Figure 3, the stud 16A includes opposed upper and lower faces 38, an arcuate forward face 40 and a straight rear face 42. The blade is shaped so that it is a close fit over the stud. The co-operation of the blade with the stud, in addition to preventing relative to and fro movement between the blade and holder, also helps prevent relative pivotal movement.
a pile wire (12) which is formed with a longitudinal slot (24) at one end thereof;
a blade holder (10) disposed at said one end of the pile wire (12) and having an opening to receive a blade (20), which opening communicates with said slot (24) formed in the pile wire (12);
a blade (20) which is located in said holder (10) and extends along the pile wire (12) with a base portion of the blade (20) located in said slot (24), the blade (20) having a tip portion (34) at an end of the blade (20) furthest from the blade holder (10); and
an abutment (26) which extends over a portion of said slot (24) above said tip portion (34) of the blade (20) so as to prevent said tip portion (34) coming out of engagement with said slot (24):
characterised in that the blade holder (10) and the blade (20) are provided with respective parts (16,18) which interengage to inhibit movement of the blade (20) longitudinally in said slot (24) in both directions along the slot.
einen Klingenhalter (10), der an dem genannten Ende des Florgewebeschneiders (12) angeordnet ist und eine Öffnung zur Aufnahme einer Klinge (20) aufweist, die ihrerseits mit dem im Florgewebeschneider (12) eingeformten Schlitz (24) zusammenarbeitet, eine Klinge (20), die im Halter (10) angeordnet ist und die sich entlang des Florgewebeschneiders (12) erstreckt, wobei ein Basisteil der Klinge (20) im Schlitz (24) angeordnet ist und die Klinge an ihrem dem Klingenhalter (10) am weitesten entfernten Teil eine Spitze (34) aufweist, und
einen Anschlag (26), der sich über einen Teil des Schlitzes (24) oberhalb der Spitze (34) der Klinge befindet, um zu verhindern, daß die Spitze (34) außer Eingriff mit dem Schlitz (24) gerät, dadurch gekennzeichnet, daß der Klingenhalter (10) und die Klinge (20) mit entsprechenden Teilen (16, 18) ausgestattet sind, die miteinander in Eingriff gelangen, um eine Bewegung der Klinge (20) in Längsrichtung des Schlitzes (24) und in beiden Richtungen entlang des Schlitzes zu verhindern.
- un fer à velours (12) qui comporte une fente longitudinale (24) au niveau de l'une de ses extrémités;
- un porte-lame (10) disposé au niveau de ladite extrémité du fer à velours (12) et qui présente une ouverture destinée à recevoir une lame (20), laquelle ouverture communique avec ladite fente (24) ménagée dans le fer à velours (12);
- une lame (20) placée dans ledite porte-lame (10) et qui s'étend le long du fer à velours (12), une portion formant base de la lame (20) étant placée dans ladite fente (24), tandis que la lame (20) possède, au niveau de son extrémité la plus éloignée du porte-lame (10), une portion formant pointe (34); et
- une butée (26) qui s'étend sur une portion de ladite fente (24) au-dessus de ladite portion formant pointe (34) de la lame (20), de façon que ladite portion formant pointe (34) ne puisse pas se dégager de ladite fente (24):
caractérisé en ce que le porte-lame (10) et la lame (20) sont pourvus de parties respectives (16, 18) qui s'emboîtent l'une dans l,autre pour empêcher la lame (20) de se déplacer longitudinalement dans ladite fente (24), dans les deux sens le long de celle-ci.